PC to HDTV

OK, this isn't exactly a new topic but her goes, I joined this site today and I would like to know if this will work before I spend any money.
I have a 60" SONY LCD HDTV I would like to hook it up to my PC. I have one HDMI connector on my tv and I have a 5 port HDMI switch box that I use for HDMI DVD player, and XBOX, I have DVD and XBOX and HDTV connected to 5 port HDMI switch box and the box connected to my HDTV, if I get a good video card can I go from the video card to the HDMI switch box and get a good PC picture on my TV? and what type of vedio card is better, should I get the one with DVI or do they make a HDMI out video card, I have the sound figured out that wasn't a problem. hope this made sense, any ideas.

I have a 42" panasonic plasma and not sure the best way to connect to the PC.

Is it better to just connect it via normal PC port on the back of the TV or is it worth investing in a card with HDMI port?

Do graphics cards go up to the "full HD" (1080) out put yet, and does that really matter when only using PC for general usage?

A few questions I know but any help would be great.

That comment doesn't make any sence.

As americanaudiophile suggest the ATI HD4550 is a good inexpensive card to use for PC connecting HDMI cable.