I agree with Larry on converting to RGB near the source, or even better, using HD receivers which output RGB.

However, I tend to favor a high-quality prefab cable such as the CTLF3VGAMM from L-Com for the run from your distribution amps to the projectors. They're readily available in lengths of 100, 150 and 200 feet, and the signal quality is superb when coupled with a good distribution amp.

Yes, they're more expensive than cutting RG59 from the spool on the truck and terminating it at the site. However, in many cases the higher cost pays off in ease of installation, testing, and post-install support.

Hope this helps.