I'm building a new rollercoaster in NoLimits, which will be a rocket coaster. Inspired by the looks of Rita and Kanonen it should be a decent ride. The first element after the launch is an inverted top hat, into a dive loop. That's all i've built so far, you can see some screenies of the track and custom station at:- http://nldc.interfix.net/p415
I don't know when it'll be out, because i want to make it as smooth as possible!