What are your regs in PA? If your allowed scopes you may wish to consider an Elite (no sights on it). They have cantileverd recoil lug which basically free floats the barrel. My friend Randy gets half inch groups out of his Elite. I generally get inch to inch and a half out of my Extreme depending on the load.

I have an Extreme and its a very good rifle. I would stay away from the wood stocks (including laminate). Knight is much better with their synthetic stocks. As for twist they only come in two 1/28" in 50 caliber, 1/30 in 45 caliber. I' d stay with the 50 caliber as you have more choices in bullets. I' m shooting the 260 gr. Winchester Platinum tips and 100 gr of FFG Triple Seven. With this load I average 1 1/2" . I' ve also used 250 Barnes and 100 gr of FFG T7 and averaged an inch. With the Barnes and 2 T7 pellets I even got sub inch groups. I' m currently thinking about trying T/C PTX bullets with MMP sabots.