Depends on what he's doing, ChasR.
He can overclock that 2.8 to 3.2 if he's lucky, with the stock heatsink, and they'll be pretty close to equivalent (AMD vs intel) in the gaming area. The intel, with its higher memory bandwidth, will do better in data intensive operations, like video editing.
Either one will do him fine. I do tend to push people towards AMD when they're squeezing the buck, but if someone has their sites set on a particular brand of processor, I won't argue with them after the initial suggestion of the alternative route. The basic fact is they both work well and both are computing bargains at the moment when looking at the history of computing power vs price.

Yes, the memory should be faster. Some of that kingston HyperX PC-3500 in the list I linked earlier should do ya fine. PC-3700/4000 will be overkill and not worth the price unless you're into *serious* overclocking.
Agreed too that the prescott is not worth the money. Stick with the northwood.
No matter what comes out in the future wrt new platforms, they'll be coming at a price premium. The best bargains will still be northwood and XP systems. Never buy bleeding edge.

No, there won't be a ton of upgrade options, but if you buy right, you won't need to upgrade for a couple of years, minimum, anyway.
Just use the onboard sound in whatever motherboard you get. If it turns out you don't like it, you can always add a soundcard later.
Get some quieter fans.

Why deal with noise when you don't have to? That's why the sonata/SLK series from Antec are so nice - big slow 120 MM fans that run very quietly.
The epox will do ya fine.
BB