I've purchased Travel Protect, but of course, the real test of good insurance comes when you actually need to make a claim. Fortunately, I didn't have to do that. From the info I could gather, they seem to be reliable. You might want to check them out with their local Better Business Bureau.
Travel Guard and Access America both have good reputations and are recommended by many travel agents.
thanks y'all! i actually found one that will waive the pre-existing condition clause if we purchase the policy prior to 7 days after our deposit payment. this is great news! what did ppl do for information before the internet?? ;-)