I really wouldn't advise getting an engine like that until you've got WAY more experience with high performance engines. For one thing it needs a tuned pipe to get the power they mention. You'd be much better off starting with something like a Rossi, Jett or the more normal MVVS. There's a learning curve for everything we do and you can't expect to go to the top of the curve just by spending money. Don't be put off though, keep it as something to aim for.
Here's a start on the upward climb of that curve. The 80/20 fuel means they're designed to run only on what's called FAI fuel which by regulation is 80% methanol and 20% castor oil (synthetics are not allowed).