What controller can I use that will support HDTV signals? The panels we use are high res, but the controllers I'm finding are all NTSC quality...

You can purchase an HD LCD TV. They do have a few 15" one that will work, or you can go to 17" for the higher resolution, or you can use one of the offerings from johnzo, like the 10.6" kit or 15.4" kit depending on how much you want to spend and what kind of resolution you're looking for...

gs

I could be wrong, but I think he's referring to one that supports HDTV via a tuner.
So, what you mentioned about buying an LCD HDTV makes sense, but if the tuner is the real question, the ones from Johnzo have NTSC and PAL tuners, not ATSC tuners.

Yeah what I have found over from doing all this controller stuff for the 7.2" panel is that there is a really large spike in price if you want and HD tuner built in.

What I'm looking for is a controller card that I can feed HDTV from an external tuner into. Most of the boards we use are all 1024x768 or better, specially if they come out of old laptops, seems a shame to drive them off of NTSC inputs.

Ok, then what I said was not right.
So what you are really looking for is a controller that supports output to LCD panels that are 1920x1200 (to get 1080p) or 1280x800, 1280x1024, etc (to get 720p)?
And, you want that controller to support input from an external tuner outputting in 720p or 1080?
I assume that you would be using Component, HDMI or DVI from the external tuner?

Saying 'feed HDTV from' kind of leaves out what you mean.

I think I've figured this out. You get a HDTV to VGA converter and then use an inexpensive VGA to LVDS card to drive the panel