Setting up a Media Center

Planning on setting up a media center PC. I want it to be able to do a few things:

1.) Work as a DVR for analog and HD Digital broadcasts

2.) Play DVDs, with the potential of playing Blu-Rays in the near future (will wait for blu-ray burner prices to go down, because i have no need for blu-rays now)

3.) Watch internet TV, hulu etc, and play music...basic computer stuff.

Couple questions.

1.) I was looking at getting a Hauppauge TV tuner. However, I am reading that Comcast (unfortunately my only TV option), currently encrypts all their digital channels, and thus i would be unable to pick them up with my TV tuner. Is that true? What if I run the line through the comcast receiver? Is there any other way around this, or are all computer DVRs currently worthless for digital channels?

2.) How powerful of a processor is necessary? How powerful of a graphics card is necessary?

http://www.newegg.com/Product/Prod [...] -_-Product

Thanks,

~Lyuokdea