Take a look at Assassin's Thread
For the RAM, since its so cheap now id get 8gb of DDR3 1333, you may not notice a difference between 4gb and 8gb, but the cost is so small.
For the CPU you will be fine with a i3 2100, unless you plan on gaming it can do all that you are looking for.
Do you have a media server, if not a SSD will fill up very quickly when recording TV, you might want to look into getting a 32gb SSD and a 1 or 2TB HDD.
For the TV tuner, id look at the...