[beta678]

AK's don't really bolt catches by design, asides from the AK12 that I know of.

Of all the AK's you've named, only the WE has a "bolt catch" per say, but its just a notch cut out in the selector which acts to hold the bolt back. You can modify or add that style of selector to pretty much any decent GBB AK on the market yourself, though it might cause wear over time and cause the bolt handle to snap off eventually.

Also since no one has touched on it yet, are you new to airsoft?

How technically competent are you?

Are you willing to do the required maintenance and spend the extra $$ to keep a GBB up and running when parts break or wear out? I consider a number of parts within GBBR's to be "consumable" so that's an additional cost to consider.

Also, magazines. New players looking into GBBR's often overlook magazines. Gas mags are expensive and can easily add up; they also require some upkeep and maintenance so that's something to consider.