this monitor will run 640x480 just fine. i would just run the nvidia directly. the 25 is alright, but the 27 is so much....bigger. if it's not cost/size prohibitive, i would up to the bigger one. IMO bigger is better but thats just me. the 25/27 use the same/similar chassis.
the monitors are generally reliable, and Rick Nieman trolls these boards occasionally, so if you need help fixing it he's really good that way.