20 g's is going to be diffcult but not impossible. Don't for get about tax and title that could blow your 20 grand away.
Unless your going to be drag racing everyday you dont need and won't have a place to use that much power. There's alot of thing that you have to change as soon as you hit 600hp.
http://www.automotiveforums.com/vbul...d.php?t=133829
check this out it'll give you an idea of what it takes.