I would go with this keyboard... it has a built in touchpad so you don't have to worry about a mouse.
Newegg.com - ADESSO WKB-4000US 2-Tone 88 Normal Keys USB RF Wireless Mini Keyboard - Keyboards
if your going for the HTPC (Home Theater PC) setup, then you might want to get a computer with a TV tuner like JohnN suggested. You can plug in your cable right into it and call it a day... but I misunderstood your drawing... Do you already HAVE the computer?? and just need the setup part, or are you starting from scratch? What's your budget, if your starting out? Do you want to build and amchine or buy one? some of those questions will help us figure out what you need to help you.