Contemplating an XPC build

I want a super quiet XPC that I can use with beyond tv to record shows. I'll probably use it as a portable game computer to connect to my friends HDTV.

I like this Kloss unit. Maybe couple it with a 2.8 Prescott or maybe a 2.6? I know nothing of Intel procs, so I need some help here. I like the ability to underclock with a botton on the front display

It supports a PCI express card so I was thinking something cheap like an ATI X300 card?? Something that has passive cooling

HD, samsung spingpoint 160GB.

1GB of memory.

What do you guys think of this setup?