It appears that OTA does not figure into your considerations. Why is that? FWIW, here's my setup, which works well for my tastes, even though we're 60 miles from the HDTV broadcasts. Two antennas, for different broadcast frequencies. SiliconDust tuner, two channels (three on new models). PC with Indel Core 2 Duo, 2 GB memory, 320GB hard disk. This supports simultaneous recording and viewing. I use home-brew Perl to manage all of this, but MythTV would do it for you, as would, I imagine, Windows Media Center. Aside from the initial capital outlay, this has zero ongoing costs. You could get a NetFlix subscription and save a bundle.

I suggest you check out Puget Systems http://www.pugetsystems.com/. Theie prices might be a bit high, but they make up for that with superior customer service and, their systems have lifetime tech support/service lifetime warranty. Theiy are a Windoze shop, but they do know (and are not afraid of) Linux. I purchased one of their high-end laptops a few months back, and have nothing but goot things to say about their product.