The Towny is a great noped, although its going to take some work to get it to to the speeds you have mentioned.
First off, as Full Tuck said, fix all of the problems with it first, and get it running well stock, before doing and mods to it.
Read this thread from start to finish...it will give you an idea of what you 'll need to do, and what your options are.
A Biturbo made for a Tomos A35 will also work, although not as well as the MLM, and sticks up in the air quite a bit. Seen in this thread
The CDI isn't limited, although you'd want one with a curve (Ignition retarded at higher RPMs) to keep the temps down. Although most of the first post is gone for some reason, here is a discussion about the stock CDI
CDI Thread. Best bet is a "scooter" CDI off of Ebay or something. Look for one made for a Yamaha Jog that has 3 single wires, and 2 that go into a plug. Its not "plug and play", but can be connected to the Towny wiring harness pretty easily.
If you are going to mod your Towny, do yourself a favor, and get a head temp gauge. They tend to run hot when operated above stock RPMs. I seized mine a couple times before finally getting one, and am glad I have one now as it has probably saved my engine more than once!
There is a lot of info on here about these, just search. Also search for threads on the QT50, as a lot of the information applies to the Towny, too. (edited)