General rule of thumb is one processor core and two GB of RAM for each video node. The system you want to build is going to depend on how many TVs you want to attach.
For OTA transmissions, you're probably looking at a couple of the Hauppauge WinTV-HVR-2250 TV Tuner cards. For whole home DVR support, you're going to need an extender for each additional TV in your home. Either an XBox or a Ceton Echo Extender.
As for your build, I can't say without knowing just how many displays are going to be attached to this system.
Your build is somewhat over-kill. For the processor, I'd probably drop down to an 65 watt A8 APU like the A8-5500K. For system memory, you don't need 16GB, 8GB of DDR3-1866/1600 is going to be more than enough. Additionally, I think you'd be just fine with a smaller OS drive. 128GB should be more than enough for your OS and media applications.