I believe my punch is by Fiskars (the 1" circle punch). But I have used several kinds and never used one that was bad. As for punching holes in the bottle caps themselves, someone here posted a tool that they said was good. If you look at some jewelry supply shops there are metal punches that work well.
I use Envirotex Lite for the resin.
I haven't flattened any caps so I don't know the best way.