If he's gonna spend so much why only a 4870? Especially if its i7. Its supposed to really take advantage of sli and xfire (someone correct me if i'm wrong here)
i wouldnt go as far a three way, for the simple fact that it doesnt help out too much to add a 3rd card until you get to real high res (1920x1200 or more)... but it could easily be done on a $3k budget
If he only wants one 4870 he can buy me one too with that amount of cash. Put in a good word
If he thinks thats a bad idea (cant see why anyone would though) think about getting 2 gtx260s or an hd4870x2 and getting a nice high res screen with it - depending on what he already has...? As for the the cpu, the 920 is the best deal, as the others are way overpriced.
You'll also want a case (but i'll leave that up to you, because you probably won't like what i will)... I would, however, add a second HD 4870 (because its cheaper than getting a single 4870X2) if you've got the money
oh yeah... you also need a CPU cooler... there are a bunch of coolers with 1366 brackets now... i know scythe, noctua, Tt, coolermaster, ocz and a bunch of others have brackets available now, but there are very few specifically designed for 1366
it feels like i missed something, but i cant figure out what... whatever... if i did, either ask me, or im sure someone else will chime in with an answer
actually... you know what.. screw the DS4... Foxconn Renaissance FTW!
with the renaissance and 4870, it'll be $1111.92 after MIR (1341.91 with dual 4870s), and with the Core 216s, it'll cost $1149.92 with a single card or $1397.91 with an SLI config