Avoid all single chips if you are sensitive to rainbows, adding segments to the color wheel might make it less noticable, but you are still likely to get the eye fatigue from your eyes/brain assembing three distinct images displayed one at a time into a full color image.
Check out this demo for more info:
[Link: pro.jvc.com]Like scott says above, look into true 3 chip models. and in your price range there are quite a few LCDs and a few D-ILAs as well.
Someday in the way distant future, a broad selection of 3 chip DLP models will be available under $10K and alongside models with D-ILA/LCOS technologies, bringing rainbow-free images to the bulk of the home theater market.
IMO, single chip DLP will be seen as the compromise that it is, and it will be offered at super low ($1k-$3k) pricing for the commercial crowd and DIY home theater guys that buy online and at warehouse clubs.