The GeForce 4 TI series cards should support what you need, the choice between the models should be made on whether you require high 3D performance (their 2D performance should be very similar). I run a TI4400 at up to 1920x1440 (60Hz), dual headed. If you are working primarily with images this should be a fine card.
1940x1200 is a non-standard resolution, I have never used or tried this.. if you are concerned that it is possible on this card I will investigate for you (X can in fact create any resolution you desire.. you just may not be able to display it ALL on the monitor at once).
The nVIDIA drivers should still support Red Hat 7.2, but I think driver versions up to at least 41.91 should be fine.
There are known issues with the OpenGL libraries with older Red Hat systems, you should be aware of the dynamic loader caused problems mentioned in the driver readme (search the text readme for dlopen
The latest driver (1.0-5336) readme is available here
. The driver archives page has the older drivers if you need them, and the readmes are probably still on the nVIDIA ftp (where this readme comes from).