i have a Mac G4 at the moment i was running vegas on pc but my budget is 2000
Yeah, you can definitely get the base 15" MBP for $1800, and that should run Final Cut Pro fine. Instead of getting the $2000 version, I'd recommend adding the Hi-Res, anti-glare BTO on the base 15", as both those options should greatly help video work.
what's wrong with Premiere? Final Cut still isn't multithreaded, and no one really knows when it'll finally be updated.