I have the 4'x5' Defender rack on my Liberty KJ and I really like it. If you get ratchet straps with hooks that are big enough to fit around the steel tube that they are made of then you're all set. I can get up on top of my Jeep and walk around on the rack in order to tie cargo down, so it's strong (I'm 175 lbs on a good day). It also has light tabs front and rear. I plan to use one of the rear tabs to mount my antenna when I get my HAM radio put in.

Before I got the Defender, I bought a Surco off of CL and mounted it to my Rocky Road roof bars and didn't like it. IIRC it is made of aluminum and is not very strong and sat too high for my taste. When I bought my Defender, ORU welded some seat tabs to my roof bars and then mounted the rack directly to the tabs and it is super strong and sturdy.

If you go with the Defender and have them mount it, ask for Kenny, he's a really cool dude and knows his stuff.

Good luck with your choice!