Everybody mentions the bar 10 for all the upgrades that you can get. The barrel is full metal, and the grip is plastic, but its got a rubbery feel to it, it is plastic though. It is pretty nice & comfortable, Just continue in research and get what you want.
as for the fps, check this out.
http://shredderscs.proboards.com/index. ... =80&page=2(Remember, FPS isn't everything...) Just note that he made the spring and I think some other parts on his own, that and that fps range is not something you would want on a field. I'm no expert, but the bar 10 was my choice(and only experience so far). Be aware that the stock sears have numerous reports of wearing out pretty early... (From what I have seen, and mine did it while zeroing in my scope.) I'm sure somebody with more experience can give you a better reply.
Best of wishes to ya though.