Thanks for the reply. I would be all for building a PC, never done it but I'm not against trying it out if it will get me a better HTPC for cheaper. I linked to the TV tuner cards in my original post and I'm pretty pumped you linked to the same ones. What would be necessary as far as processor specs and what not. Maybe even a suggested place to start as I've never built a computer.
If you are thinking of building your own PC (YAY!) I would say start with the basics...
First you need a case... the type depends on you. There are regular towers, slim cases that are designed for a cabinet or underneath the TV, and even Micro Cases that are small and compact. Be aware that the case has a lot to do with the cooling of the PC, the smaller Micro Cases tend to overheat... Since you are a first timer, I would suggest you just stick to the regular towers...
Again, newegg has a wide variety of decently priced hardware...
Cases:
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2010090007+1054808287+1295819208+105510017&Configurator=&Subcategory=7&description=&Ntk=&SpeTabStoreType=&srchInDesc=
After you have chosen the correct case, I would suggest you move on to the motherboard... something important to take into consideration here is that the motherboard is dependent upon the processor that you choose, and vice versa. While looking at motherboards, also look at the compatible processors.
The processor you choose should be based on the amount of work you intend your computer to do, and how quiet you need your PC to be. If you want a silent machine, you will need a processor that uses low amounts of power, thusly running cooler than higher end processors.
AMD Processors (all 64bit):
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2010340343+50001028+1266316752&Configurator=&Subcategory=343&description=&Ntk=&SpeTabStoreType=&srchInDesc=
Intel Processors (all 64bit):
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2010340343+50001157+1266316752&Configurator=&Subcategory=343&description=&Ntk=&SpeTabStoreType=&srchInDesc=
The motherboard should have either on board hi definition audio outputs, or none at all, as you can get a sound card later on down the line. There are even video cards that have a sound processor built right in, thus allowing you to use one single HDMI connection for both hi def audio and video. Most motherboards will also have on board USB, Firewire, network, and keyboard/mice connections. You must also make sure that the motherboard supports the processor that you have chosed... you can do this by checking what SOCKET TYPE the processor is, and then searching through the two choices below and matching a motherboard with the processor (make sure you choose either the AMD motherboards for an AMD processor, or INTEL motherboards for an INTEL processor).
Intel Mobos:
http://www.newegg.com/Store/SubCategory.aspx?SubCategory=280&name=Intel-Motherboards
AMD Mobos:
http://www.newegg.com/Store/SubCategory.aspx?SubCategory=22&name=AMD-Motherboards
After those items have been chosen, you can move on to the specifics.
Did the Motherboard have on-board hi def audio? If not, go to newegg and search for PCI audio cards...
Find the correct video card... try for something with HDMI, up to 512MB RAM, and sometimes a TV tuner. There may even be ones with audio out supported. If you get an AGP video card, make sure the motherboard you have chosen has an AGP slot. If the video card is PCI, you are solid.
Find RAM that is compatible with your motherboard. DDR2/DDR3 (You can ask for more detail later, once you have picked out the motherboard)...
Find a SATA Blu Ray burner/reader...
And a media reader/writer if need be.
If the video card you have chosen doesn't have a TV tuner, find that next.