Some have better reviews. I never really gotten into the tv tuners, I just got the www.popcornhour.com and it's silent which is what I was looking for.
But look into an AMD build, will cost you less.
For motherboard look into a micro atx.
A very low powered PSU will do like a 400W or less.
P2X3 710, stock + undervolt via K10 Stat
Biostar TA790GX XE
cheapo 2 X 2 DDR2 800
Hitachi 1tb
Shoebox casing
Antec Earthwatts 380
My cookie cutter HTPC for clients with a lot more horsepower than those Athlon x2s