Help..recommendations please.

[Horatii]

Hi
Im hoping to upgrade my sons PC for Xmas and would like some advice/recommendations please.
He uses hi PC mainly for gaming. He plays Counterstrike Sourse, Team Fortress and games alike. But his PC struggles when he trys servers with more players on or when theres a lot going happening on the screen. So I would like to upgrade the following:-

1) CPU + Heatsink
2) Motherboard
3) 2gig Memory (3-4gig if its a worthwhile upgrade?)
4) Graphics Card(s) (Are 2 cards better than 1 of the same price equivalent to the 2?)
5) PSU to run the above.

I would like to spend £500 or less, but i will consider going a little higher if the extra cost is justified.
Im hoping to put something together that is reliable and excellent value for money. Im not looking for something that I can overclock as its somethin ive never done or will do.

ALL recommendations, advice and comments are welcome.

Thanks in advance.

 

[BillytheImpaler]

This is what I'd get:

If you were looking to spend the rest of the budget you could get another 2 GiB RAM, which would require a 64-bit OS, a dedicated sound card, I recommend the XtremeMusic, or an aftermarket CPU heatsink for quieter operation.