Check out the pictures HERE
. I'd say you'll be fine with either a DVI-D single or dual link, or a DVI-I Single Link cable (the latter is probably the cheapest - the above site also sells cables & adaptors). Just don't get a DVI-I Dual link because while it'll fit your video card, it won't fit your monitor.
Also, since your video card must convert the internal digital video signal to analog for output to the RGB port, the LCD monitor must reconvert back to digital at its end, in order to use same. Better to keep the signal path all digital with any of the above cables.