In general, get a gt220, as it has built in audio hardware, so that you should get audio without clock drift relative to the hdmi output. It is also powerfull enough to do temporal spatial deinterlacing on 1080i material.
what do you think about
NVIDIA's GeForce GT 430 http://www.anandtech.com/show/3973/nvidias-geforce-gt-430
seems it's the best choice for vdr/htpc
- more cold than gt220 - more powerfull - HDMI 1.4, - 3D over HDMI - Ethernet channel - Audio return channel - 4k × 2k Resolution Support