Not really for LFS. He want's it for much for modern games which require alot of power, like Crysis, GTA IV etc.
Would you say SLi is not a good call then? I only selected it due to him wanting to run very up to date games at the highest possible, so i guessed he might need some more video memory. I have SLi on my rig and it sure does help!
Plus three 22" monitors and a second graphics card to run the 3rd screen. This second card can be just a tiny one, like a £25 Radeon 4350, as it's not doing any graphics processing, just outputting an image. If you're not feeling that extravagent (although I heartly reccomend it - I'd never go back to less than 3 screens now) then get a big single screen, 27" ones can be had for around £300.