Building a Multimedia PC

Hey guys, I'm a noob at building PC's and I decided to build one for my 40" LCD TV but I have a few questions that I hope you guys could answer before I jump in.

1. I want to record TV on the computer in HD format, do I need a special TV Tuner that will do this or will all of them have this option?

2. The mobo I chose only supports ATA100 hard drives so will ATA 7200RPM speed be enough to record TV or do I absolutely need SATA.

3. I chose a GeForce 7300LE 256mb video card, will this be sufficient for what I'm doing?

I have more questions going off of these so I'll post them up later. Thanks in advance!