Anyone have experience with gasoline RC airplane engines?

[Blarg King]

So like the title says, I'm looking into buying a little gas engine for an RC plane for a project (Yes gasoline, not a glow fuel engine since I have nowhere to buy glow fuel) and I've seen a few places to buy from like HobbyKing and HobbyPartz but I've seen a bit of negative reviews about those places.

Also, while I'm at it, what are some reputable brands of gasoline RC engines? I've seen OS mentioned a few times, but are there any others I should consider?

Thanks!