Chuck,
FWIW, I'd say build the SS60. One with retracts would be AWESOME. You can get a set of electrically operated retracts that are easy to install and setup amounts to plugging them into a "Y" harness and plugging the harness into your receiver in the gear slot and that's it!

You can see them at
www.Lado-Tech.com. I ordered a set for the 60 size GP Ultrasport kit that I want to build this winter.
Good luck with your decision on which to build and maybe start a build thread for the SS60 and retracts with lots of pics.