There is a lot more involved then just hops. Lagers, IPA's, pale ales, etc all have different grain builds and hops. If you are wanting to clone someones beer I suggest you try and figure out whats in it first, what do you taste, what do you smell, whats the mouth feel, try to find a clone of the same beer someone else has already tried.
To get an idea of what hops are in a beer look at this post and see all the hops,
It defines the flavor you can get from each as well as uses.
2 ROW MAX USE 100% 2L
Use as a base malt to provide enyzmes for conversion. Suitable for all beer styles
6 ROW MAX USE 100% 2L
Suitable as a base malt for any beer style, this malt has high enzyme activity sufficient to support a high percentage of specialty malts
CRYTAL (CARAMEL) MAX USE 20%
10 °L Lends wort a golden color and a slight caramel sweetness. Suitable for all beer styles.
20 °L Lends a golden color and a slight caramel sweetness to all beer styles
40 °L Adds a deep golden color and medium caramel sweetness to Lagers, amber, and Ale beers
60 °L, 80 °L, 90 °L, and 120 °L Caramels in these color ranges impart a red hue and a flavor that varies from that of a strong caramel to a slightly burnt sugar. Best suited to amber, Pilsener, red ale, Märzen, and Bock styles
CARAPILS (DEXTRIN) MAX USE 20% 2L
Used to improve foam, increase shelf life, and create mouthfeel without adding color or flavor.
HONEY MAX USE 100% 1L
A very versatile malt. The intense honey-like sweetness this grain imparts makes it a nice addition to almost any beer style
MUNICH MAX USE 80% 10L & 20L
A little darker than our German Munich malt, use our Domestic Munich to add a deeper color and fuller malt profile. An excellent choice for Dark and amber lagers
VICTORY MAX USE 15% 25L
A unique, lightly roasted malt that provides a warm "biscuity " character to Ales and Lagers. Use 5 to 15 % to add a fuller flavor and aroma to Ales, Porters and full flavored, dark Lagers where a bigger malt character is desired without crystal malt sweetness.
Improves foam in all beer styles, Use to make wheat and weizen beers. Also, small amounts (3-6 %) aid in head retention to any beer without altering final flavor
PALE BRITISH MAX USE 100% 3L
Moderate malt flavor. Used to produce traditional English and Scottish style ales.
CRYSTAL BRITISH (CARASTAN)
Sweet caramel flavor, adds mouthfeel and head retention. For pale or amber ales.
BROWN BRITISH MAX USE 10% 65L
It imparts a dark roasted flavor and bitterness to a beer. Use in older styles of English ales. Try using 2 oz. - 1 lb. in brown ale, porter and stout recipes. Use in porters, brown, nut brown and Belgian ales.
CARAHELL GERMAN 10L
For light colored beer for body; hefeweizen, pale ale, golden ale, Oktoberfest.
CARAMUNICH GERMAN MAX USE 10% 50L
Provides body. For Oktoberfest, bock, porter, stout, red, amber and brown ales.
MELANOIDIN GERMAN MAX USE 15% 25L
is similar to German Munich malt, except more aromatic and darker in color. It produces a more reddish color than the gold color produced by Munich malt.
For amber lagers and ales, dark lagers and ales, Scottish & red ales.
PILS GERMAN MAX USE 100% 2L
VIENNA GERMAN MAX USE 90% 4L
European lager malt kilned slightly more than Pilsner malt. Full bodied, golden color.
AROMATIC BELGIAN MAX USE 10% 26L
Imparts a big malt aroma. Used at rates of up to 10%, Aromatic malt will lend a distinct, almost exaggerated malt aroma and flavor to the finished Ales and Lagers. Aromatic malt also has a rich color
BISCUIT/KILNAMBER BELGIAN MAX USE 10% 23L
Warm baked biscuit flavor and aroma. Increases body. Use in Belgian beers.
CARAMUNICH BELGIAN MAX USE 10% 56L
This is a caramelized German Munich malt. Use CaraMunich for a deep reddish saturated color, 5 to 15% will also lend a fuller rounder flavor, contributes to foam stability, adds unfermentable caramelized sugars, provides body in all beers, and contributes a rich malty aroma. Used for dark beers, porter, stout, red ale, brown ale, malt-liquor, amber ales.
CARAVIENNE BELGIAN MAX USE 10% 22L
imparts a rich, caramel-sweet aroma to the wort and promotes a fuller flavored beer at rates of 5 to 20 % of the total grist. It can be used in up to 15% of the grain bill without leaving the beer with too much caramel sweetness.
PILS BELGIAN MAX USE 100% 2L
Light color, malty flavor. This is an excellent base malt for many styles, including full flavored Lagers, Belgian ales and European wheat beers.
SPECIAL B BELGIAN MAX USE 10% 180L
It provides an intense roasted caramel character and ruby-red color to beers. Use small amounts (usually about 1/4 lb per 5 gallons) to add depth and complexity to dark ales and lagers or more for an intense malt flavor and aroma. Can be used sparingly in brown ales, porters and doppelbocks to add character and complexity.
flaked barley: MAX USE20%
Adds to the body and aids with head retention. Use at the rate of 2 – 12% of the grain bill. Adds proteins which promote foam stability/Head retention and mouth feel. Especially good in Porters, Dry-Stouts and Stouts, but can be used in any beer. Note: When used in amounts over 3% is may cause haziness, due to the amount of protein content. Not an issue with Dark beers, but should be considered with lighter colored beers.
flaked corn: MAX USE 40%
Lightens color and body but maintains alcohol content. Use in small quantities to add depth of character to lighter ales and lagers.
flaked oats: MAX USE 30%
Adds a silky smoothness to stouts and Belgian ales. Adds body, sweetness and aids in head retention. Oatmeal breaks down in the mash (or can be steeped) to lend fullness or that Oatmeal pucker and smooth grainy character. Use 1-1 1/2 lbs in a mash to impart the flavor of Oatmeal in your Oatmeal Stout or Porter.
flaked rice: MAX USE 25%
Lightens body, color and flavor. Provides a light, crisp finish. Used in light American ales and lagers.
flaked rye: MAX USE 10%
Gives a dry, crisp, strong rye flavor to light colored ales. Used in Roggen beers. Used as an adjunct grain in the production of rye beers. Adds a crisp and slightly spicy character. Usually no more than 1-2 lbs. (or 5-25%) to cause a dense, rocky head and a pronounced rye flavor.
flaked wheat: MAX USE 40%
Greatly increases body and head retention in most any beer. Use in small quantities, 4 – 6 ounces in a 5 gallon batch.
And choosing the right yeast will also make a difference.
Sometimes you can go the beer makers web site and they will give you an idea of whats in a beer and you can work from that, as for cloning a beer its all trial and error until you get it right.
As for where to buy your hops, your local brew supply would be best, if you don't have one close find a reputable brew supply place online and get it from them. yes you could find them on ebay but you never really know what your getting.