I sort of went backwards, Ive had two Texans ended up getting PBBA .457. Although I shot Nielsen ammo 372gr at MOA 100yd, I wanted to shoot lighter/faster, but remain 3000psi. I also wanted a more traditional rifle with ability to make changes such as fill pressure, spring changes and even barrel. I had an Extreme and they are top notch. Very powerful, some options for stocks, barrel length and tuning at different pressures. Bushbuck is also proving to be a great rifle given the EBR scores, Kip's success, and recent review by AEAC. I like that it has two power settings, like my Sam 909 and PW on Texan.
In addition, I concur with Wager. AAO (Jeremy) was great to deal with and provides some options. Spring change and increasing to a 3500psi will also provide some great results for short $$$. There are Maddog stocks for this as well. Im finding that Im settling more on what type/weight projectile I would like to shoot and for what purpose, to guide me. You have some good options there and probably cant go wrong!