For the TV tuner, you might want to think external, it'll free up your options. I know Happuage (
http://www.hauppauge.com/html/usb_data.htm) makes one, and I've never seen a laptop with one built in.
For the laptop, try winbook.com for a fast system, they'll put a desktop CPU & video into a laptop for you. I believe the M series uses desktop processors, not centrino/mobile.
http://www.winbook.com/notebooks/m/m_techspecs.html
Enjoy!