its going to ensure a good quality HD tuner, and other features that you'll want (for example, Creative audio cards, bad idea, M-Audio/Turtle Beach audio cards, good idea), and it'll keep the price down
I also don't suggest setting the PC up as the center piece of the HT, let the A/V processor do that, thats its job, set the PC up as one of many inputs to the A/V processor, get a graphics card that won't have issues with 1920x1080 output (I'd suggest a GeForce 8600GT) and a CPU that won't have issues with 1920x1080 playback (quad core Kentsfield shouldn't have a problem) in addition to ~2-3GB of RAM, and a RAID0+1, RAID10, RAID5, or at bare minimum RAID1 HD array, high quality power supply, and GbE network connection (wired)
I want to purchase a very good PC that I can use just for a Home Media Center PC. I plan on using the pc to connect to a flat screen tv and then sending the signal wireless to other tv's using a media extender.
I currently have a Linksys N router. I have cable tv and would like to find a PC with a dual tuner card option.
What other items do I need to consider and what are the minimum requirements to get a very good hd picture?