The HF set-up requires a lot of fabricating skills. There's no kit but a lot of threads here from those that have. Due to their size at 99cc it's not road legal in most states but that's no problem on the lake bed. That's where Thrust set the World Land Speed Record.
The HT kit with a bigger gear is by far simpler and will do the job. You should keep an eye on your airfilter there, though.