Building a PC for a friend,

What he already has
USB / firewire - CD/DVD RW
PCMCIA 802.11b/g compatible wi-fi card
Optical Mouse

What i'm after and decided on (suggest improvements if necessary within same price range):-
Geforce 6800GT 256MB - PCI-E version (not AGP 8x) (not bothered about the manufacturer)
Corsair / Mushkin Memory DDR400 - 1GB unbuffered - preferably with some form of heatsink
Gigabyte GA-K8NF-9 Motherboard (or other nforce4 chipset based motherboard... pref. with integrated sound chip)
AMD Athlon 64 3500+ (939 Pin version)
Samsung SyncMaster 710T - TFT 17" Monitor (or equivalent, basically any reliable TFT monitor woth max 12ms response and preferably with DVI)
Maxtor Diamond Max plus 9 120GB HDD U-ATA 133 7200RPM (although U-ATA 150 maybe better but looking at cost effectiveness, and if poss 10,000RPM would be nice :) )

What I haven't decided on yet but know rough specs...

PC Case - Preferably one with 2-3 internal Fans
PSU - 350-400Watt preferably with 2 Fans
Keyboard - PS/2 not fussed really, even a cheapo secondhand one will do.
Floppy Drive (not sure if i need one)

Optional :- DVD ROM drive - do not need a burner as i already have a USB One

Want as quiet as possible unless anyone knows a cheaper method (e.g. liquid cooling but havent looked into the costs of this yet)

Your PSU looks a bit "skinny".
Go for the new quiet Antec Neopower 480, see e.g. here: http://www.komplett.ie/k/ki.asp?sku=305077&cks=PRL or any similar with a 12cm fan.
If you plan on overclocking, get faster memory

Have a look here at various AMD64 and it's flavours http://www.behardware.com/articles/531/page1.html

The PSU is more than adequate if it is a quality brand.