This is the one I've seen before. It was built and flown by George Gurney at my old club and featured in SE Modeller. It was electric.
If I scratch build one it will be electric also. I fly at a glow club that probably wouldn't be real friendly to the idea of a high start or winch running around. Every sailplane I've built has been electric since my first Spirit which started out non-electric but I got sick of chasing the high start around.