They have a good reputation as far as I know, but I always reccommend Bob Supplee and Suplpee 4wd.
His service is second to none, and his prices are comprable to 4x4groupbuy. I bought my lift kit from Bob and it was slightly cheaper than 4x4groupbuy. His service was awesome and the kit was here within a couple days. If I am buying a new part, I always check with him first.
Bob Supplee. (405) 799-8977
http://www.jeepreviews.com/where-to-buy-jeep-accessories/286/bob-supplee-reviews/