Hey Buddha, bm here is gonna' blow by both of us pretty quick, he'll be in the red before you Bud.
Sorry p8ntboy, this is your thread. Try Crom's advice, and look for a sweet second-hand one. I'm a looong-time 'Mag owner, and I'm going to tell you, all you need is a barrel. Compressed air would be ideal, and a .45 frame would be nice, but performance-wise, the barrel is all you need. Heck, if you can get an old foamie bolt, that would be great as they're a little easier on your paint. Good luck.