Best Av Receivers Under 300 Which Video Card Do I Need??? (HTPC 1080p A MUST!)?

Which video card do i need??? (HTPC 1080p a MUST!)? - best av receivers under 300

Ok I leave it to experts. I wonder which card to me is the best for my outburst of money. I'm not a player, I'm a fan of video (BluRay). I am interested in spending under $ 300 .... You can keep the price as low as possible, if possible.

That's what I ... Please enter only suggest what you think is the best way.

52 "Toshiba Regza WTH 3 HDMI, etc, etc. .. (Full 1080p)
Onkyo AV receiver with 3 HDMI (1080p)
... Of course I want to keep my photo @ 1080p.

Do I need an AGP graphics card with HDMI output? If so, you support it?

Or should I use DVI cable (DVI, but it is only 1080i ????)

I just ran cablefrom my PC to the TV? or was it the same thing if I go through the Onkyo Receiver?

Any help would be very grateful.