i7s on socket 1366 are triple-channel, so that means he can choose between 6GB or 12GB, and he's likely doing the latter.
Now if you ask me if he should go with an i7 to begin with, I'll flatly say "no".
He said something about an i5, so I think the socket 1155 is what he had in mind, no?
Regarding RAM, you can always get 8GB now and 8 more later, if you see a need for it. Just make sure you get the 4GB modules. (Tho, I like the idea of RAM driving the swap file, checking it out now.)
Regarding power supplies, big wattage is not the answer, it is the efficiency that is important. Bronze rating is good.
If you want speed on OS start-ups and game loading, get a SSD, it is worth the money. With a 1500 budget, you can get a nice 256GB drive that will hold you OS and most of your games. But that is just my opinion, but I know from having one that it makes a ton of difference. SATA-II or SATA-III notwithstanding. Tho, to stay ahead, I would go with SATA-III to stay ahead of the game.
Video cards is a hard thing to shop for. It is important to read up on reviews. Most, test with games. Just remember that dually cards have there problems. Just remember that it seems that 57xx are more powerful than 68xx, but more power hungry. And the 69xx are more powerful than either and a little more power hungry. And of course, the price is effected.
This is what I would do, I would go on Newegg just to build the dream machine and then play with the prices by upping or going down on parts/prices. And save them on wish lists, even if you don't buy it from there.
Just my 2 cents. And good luck and keep bouncing things off us.
A fact is a simple statement that everyone believes. It is innocent, unless found guilty. A hypothesis is a novel suggestion that no one wants to believe. It is guilty, until found effective.