Probably the 5S LiPo, but changing the gearing will let you know for sure.

Well i thought about going higher and seeing what happens but its over 40 now ( i haven't radared it yet, but i have a 9XL and 5s in the G2R and it radared at 37mph) and its faster than the G2R

I've just got a MGM12032 from Mike. The thing looks very good and well built.
I had to read the instructions multiple times to get the bottom line of the way to program it. It does not seem that difficult, now. I'm not ready yet to try it out, but hopefully a few weeks later.

well I ordered the quark today...so i think it was a good choice....