You are correct on the first part. This is because the version 2 is designed to accommodate a non-tapered cylinder head. EDGI makes a good AEG barrel. There is really no way around a higher price for a good barrel. Most brands have the 430mm cut I believe, just shop around. Yes, you can use the FireFly bucking with the set up. (given it's an AEG bucking). Just be sure to use a normal nub.