My first Build: Phase 1 - parts

Hey,

I'm looking to start my first XBMC build. This will be a Windows build and I will need it to do a little bit more than just XBMC.
The build needs to run at least Subsonic and uTorrent but potentially other services and applications as required.
My main usage for XBMC will be local 1080P content but I would want it as capable as possible.

So far I've only purchased the chassis: BitFenix Prodigy
I can potentially get this supply at a bargain price: Corsair TX550M

The next parts I need to decide on...
Mobo: I was thinking the Asus P8H77-I because it is the cheapest Mini ITX board with 6xSATA that I can get my hands on
RAM: 2x4GB should be more than sufficient. Probably something like Kingston ValueRAM 1333. It is cheap and compatible.
CPU: This is one of my biggest questions. I don't want to get the bare minimum for running XBMC only considering I want the build to do more than just that. Is there a major advantage in going for IvyBridge over SandyBridge at the moment? Should I be looking at a T-series CPU? Dual or Quad? Potential options range from i3-2120T (2.6|Dual|35W) to i5-3470 (3.2|Quad|77W)...
GPU: I'm also quite clueless here. I'm assuming the GPU will only be used for XBMC. Something from NVidia, something low power, something passive? GT 610 1GB?
SSD: 60GB SandForce2 should be good enough for a OS drive?
HDD: Any recommendations here? Green, low power, low RPM models would be what I'm looking for, right?

Any assistance would be appreciated