Need Video Capture Selection Help !!!

[amorg7777]

I have purchased a DELL Vostro 420 Quad-Core 2.66Mhz/3GB DDR2 Ram/2-250 GB SATA HDs/ATI Radeon HD 3450 (512MB) w/HDMI Output
.
I want to install Mythbuntu 9.04 and use this PC as my PVR. But I cannot decide which Video Capture devices to use in my set-up. Do I use the (outside) boxes ..... like these that follow -

Hauppauge WinTV-HVR1950 USB TV Tuner
Hauppauge 1212 HD-PVR High Definition PVR

Or maybe (inside) cards ..... like
Hauppauge WinTV HVR-1800 TV Tuner
Hauppauge HVR-1250 PCI-Express , etc.

I just want a simple set-up to record HD programming off of my Comcast (Motorola) HD cable receiver. And to be able to watch the progams at a later date & time.

Any and all comments and suggestions will be most welcomed and greatly appreciated. TIA, amorg777

[mitchell2345]

To capture HD of your cable STB your only choice is the HD-PVR.

You can use other digital cards to record clear QAM but that wont be off your cable box. To get an idea what you would get see:
http://www.silicondust.com/hdhomerun/channels_us

Mitchell