Since you want to have something that's easy to load/unload, have you considered a small trailer? I know it might be more expensive, but it seems like the best option in terms of ease of loading/unloading. (*Edit, I just read that you don't have a hitch. Still might not be a bad idea if you're willing to invest in one though.)
I myself just picked up a j-bar rack for my yak. J-racks in general are a pain in the ass to load and unload alone, especially with a lift since the yaks are so big and awkward. However they are cheaper and simpler than other rack options i saw. The model I picked up was the yakima hullraiser aero. I do not recommend it for two main reasons:
1. The straps included with the hullraiser do not clamp very tightly. I have a set of ratchet straps I could use instead, but at $150 I think the ones included should be pretty damn sturdy. These however, are not.
2. The clamps that hold the j-rack to the crossbars are plastic and seem to flex quite a bit when torqued down. With a kayak on the roof acting as a wind sail, it's hard not to be concerned about this flimsy piece of plastic since it's one of the things keeping the kayak from taking off down the highway.
If this rack had costed $50 bucks, maybe I'd keep it, but at this price ($150) I am disappointed with it's quality. I'll probably exchange it for the thule hull-a-port j-bar rack, which seems to have a better design.