I have some and I didn't look to see if there are different ones. I bought them on Amazon a couple of times. They work great when you're on the go with a keg.
I looked into this and basically non food grade will have more contamination but likely not harmful. But you probably want to avoid the ones sold specifically for tires inflation those are considered industrial standards much less regulation.
I've also gone through a couple of mini-regulators. I'll try the Kegland one next. They say it's more hard wearing, though it doesn't have much competition to be considered better.