PSU mini-itx

I have the following parts available that are giving me a growing urge to make a tiny computer:

defunct Aerocool Airpoer PSU
1GB PC3200 DDR2 (from malfunctioning notebook)
40GB HDD from said notebook (PATA)
Quiet 80mm fan from PSU, with standard connector

I like the idea of a mini-itx board, but this would be my first foray into effectively a self modded case. Basically I'm after motherboard suggestions as I'd like to go fanless, but am not sure about heat issues. Secondly, I have little idea about extra parts - I know about mini-itx.com - but need suggestions. Finally I would like to use this as a normal computer (OK, few games) not as a firewall or HTPC. Is using the HDD the best option, or could I go with booting Linux from a compact flash drive/memory card?

you could also try www.linitx.com for some more ITX parts. What kind of games are we talking?

Thanks, that's given me some ideas