I use the small one and a strap on cart in the front (4 wheels). So, I don't have to lift the weight in addition to pulling the kayak. You may not need this for an Outback.
Once to the beach I take the carts off and pull the boat out beyond the shallow area and install the mirage drive before getting on. I find that coming in tends to be the most dangerous step and have learned the hard way to get out of the boat beyond the waves, get the boat between me and the beach, and let the waves pull the boat in for me. That way I have total control and I am not in the firing line of the boat+waves. I don't mind the swim since it makes it much easier and safer (especially if the beach is a bit crowded). Thought I'd share that....
Yellow Adv Island