Wolf's is decent, but if all your doing is watching media, I would swap the AM3 board/CPU for an i3-530/H55 board. They make the best HTPCs right now. I also wouldn't touch the OCZ RAM. It's really hit or miss on what works.
I would sell the i7 and build this:
CPU/Mobo: i3-530 and Gigabyte GA-H55M-S2H
RAM: Kingston 2x1 GB 1333 mhz CAS Latency 7
$58. 4 GB is nice, but not really needed for an HTPC. If you want 4 GB, this kit
is good at $95.
HDD: Seagate 7200.12 1 TB
$90. The 750 GB is going to be slower.
Case: The above is fine if you want an HTPC case. I personally don't care for them...
Rest is the same (maybe 32-bit for the OS if you go with 2 GB of RAM)
Total: $567 w/ 2 GB, $604 w/ 4 GB