Connecting nvidia GTX 280 to TV ?

My current PC setup is:

GPU: XFX nvidia GTX 280 (with dual dvi output ports)
Monitor: Samsung 22" inches SynMaster226BW with resolution 1680x1050
CPU: Intel Quad-Core Q9300 2.50Ghz

I'm planning on getting an HD-TV soon to replace my monitor so I will use the TV as a monitor screen and also to be able to game on a console. I say the TV will replace my monitor because of the lack of space to keep both as a dual monitor system. The TV's I have in mind are either the (Sony 22" KDL-22ex420) or the (Samsung 22" LA22C450).

The Sony has 2 HDMI inputs but no d-sub input unlike the Samsung TV which has only 1 HDMI input and 1 PC D-sub port.
Both are 22" and are HD-ready so 720p max and the websites list a resolution of 1366x768 compared to my current 1680x1050.

I am a heavy gamer and also internet surfer and the use of a console (ps3) is not a complete substitute for the PC so my question/concern is that if I connect my gpu to either TV's will I notice a considerable drop in the image?

Is there a difference in connecting the GPU to TV via HDMI or D-sub ?
DVI > HDMI vs. DVI > D-Sub

I apologize if i'm all over the place with this post, I will try my best to clarify any misunderstandings.

My current PC setup is:

forgot to post some links:

GPU: XFX nvidia GTX 280(with dual dvi output ports) (http://www.nvidia.com/object/product_geforce_gtx_280_us.html)

Sony 22" KDL-22ex420 (http://www.sony-mea.com/product/kdl-22ex420)

Samsung 22" LA22C450 (http://www.samsung.com/ae/consumer/tv-audio-video/television/lcd-tv/LA22C450E1XZN/index.idx?pagetype=prd_detail&returnurl=).

For console gaming