I got my tower (replaced faucet with perlicks and added longer beer lines) for pretty cheap- after customization though, I think I would have made out better buying from somewhere else where I could have done it upfront. Other then that I've read positive reviews and I didn't have any problems with my purchase.
I purchased a basic upright refrigerator through the door from KegCowboy.Com in early 2006 because they were the least expensive option and the kit is still working great. I went back to them this past spring to build my homebrew kegerator and was amazed by how much lower the price was compared to every other option I saw. The dual product regulator I purchased was $25 less than the next lowest option. I think they are a good company and would recomend them.
I have purchased the Chrome Ranger and it is going strong. I liked the Micromatic products but I was able to get the same kit for $80 less through KegCowboy.Com. I added a manifold and even though it is nothing fancy (I actually found a really cool spliiter at kegkits but wayyyyyyyyy too expensive) it also works flawlessly. Go with KegCowboy they seem to really value their customers and take pride in their kit.