How about the rollers for your kayak? I am about 5'4" and can get a kayak up on a car that way (haven't tried an SUV). All you have to do is get one end on the rollers and push. Saves your having to lift the whole thing over your head (a cumbersome process even with 2 people, I've found...)

We discovered that even our old V70 volvo isn't wide enough for more than 2 kayaks (can't get the bikes on top too), so you may have a width consideration depending on the type of vehicle and kayak.

Good luck!