i would get a pedator 212 kit, the dual 2 strokes will probably be more expensive and more completated, and harder to start ( if one starts and the other refuses) it will be cheaper as well.
here a link to the kit
https://www.gasbike.net/products/gastrike-212cc-trike-engine-kit
good luck man!
here a link to the kit
https://www.gasbike.net/products/gastrike-212cc-trike-engine-kit
good luck man!