media centre PC advice needed

[judge john]

ok time to update this thread. after talking to my brother a bit more and clarifying exactly what he want i have come up with some specs. only problem is this stuff gets quite complicated so i could do with some advice.
he's told me that he wants a dual core CPU, as he has seen other MC's with them. i personally told him that unless he is planning on doing some major multi tasking it wasn't necessary, but he insisted. also he wants quite a powerful comp to last quite a few years. so here's the specs I’m looking at;
CASE:
http://www.xcase.co.uk/acatalog/Silv...e_lascala.html
Silverstone seem to have a great range here so I’ll get him to pick one of these

CPU;
he said he wants a minimum P4D 2.8GHz or AMD equivalent
http://www.ebuyer.com/customer/produ...uct_uid=102623
http://www.ebuyer.com/customer/produ...duct_uid=94640
so which is better? i am inclined to go with AMD as it seems they are normally better and as it's a media centre it is important you keep temps to a minimum, so AMD's running cooler than P4's is a plus.

Gfx Card;
http://www.overclockers.co.uk/acatalog/6600_Series.html
this is very good as it's fanless and quite a capable card. may upgrade to a 6600GT depending on his gaming needs.

HD's;
Western Digital Caviar SE16 320GB 3200KS SATA-II 16MB Cache - OEM
http://www.overclockers.co.uk/acatal...ital_sata.html
seems to be cheaper than buying say 1 500GB HD. only problem is it's OEM. and as noise reduction is paramount what maker has the quietest drives with least heat?

Mobo;
Pretty much any standard ATX, PCI-E, Dual core, will do.
AMD one;
Asus A8N-E nForce4 Ultra (Socket 939) PCI-Express Motherboard (MB-088-AS)
http://www.overclockers.co.uk/acatal...ocket_939.html
Intel one;
Asus P5GPL-X Intel 915PL (Socket 775) PCI-Express Motherboard (MB-128-AS)
http://www.overclockers.co.uk/acatal...herboards.html

PSU;
Picked this as it’s quiet but I think it maybe a bit of overkill. Also not to cheap.
Zalman ZM460-APS 460W ATX2.03 PSU (CA-003-ZA)
http://www.overclockers.co.uk/acatalog/Zalman_psu.html

Memory;
i have 1.5GB Crucial pc3200 lying around

DVD-RW;
http://www.ebuyer.com/customer/produ...duct_uid=97063
or anything similar.

so any suggestions about parts and does it all fit together fine?