Well I believe Intel's o/b gfx solutions are actually pretty decent for image quality, but it would be a good idea to get a decent add-in card with DVI, you could try it with the Intel solution and if it's unsatisfactory then consider your DVI options.
Rad9000 is an excellent budget choice with very decent gaming ability and full DX8 hw (if that's important to you). It also sports great IQ (not much diff when using DVI though), dual display, great TVout and hw MPEG playback and enhancement. If you want a bit more for your money then a Rad8500LE-128MB shoud be under $100 and offers much the same features as the Rad9000 but is a lot faster for gaming. If you want a little more you could consider GF4TI cards, the 4200 is esp good value for money. If you aren't so interested in 3D then Rad7500, GF4MX420 or even an old Matrox card (G200-450) with DVI are good options, saying that these are all still much faster than Intel o/b gfx!
If your CPU is pretty slow (< 1ghz) there isn't huge point getting anything better than Rad9000 although Rad8500LE would still be better. Anyway, if your screen is expensive it makes sense not to skimp on the device feeding it the signal!