Hi-
OK- I understand the desire to keep the ADC....
If you can, get a Mac Edition Radeon 9000 Pro. It will have ADC and DVI. The Geforce4 Ti has some power, but it does have a few compatibility problems.
The 9000 can run a monitor and a LCD TV with a fair amount of resolution choices, and will work well in the QS.
Though currently a different card, I used a 9000 in a QS that is a media server. It is connected to a 37" LCD TV via DVI to HDMI. The 9000 worked well.....
Because the DVI port is DVI-I, it has integrated analog. A DVI to VGA adapter can be used.
Better, is to use a digital connection. A DVI to HDMI connection will work the best.
Of course, though normally HDMI has integrated audio, the DVI doesn't, so audio out is separate.