Re: Engine kits
Howdy Fago, welcome.
Honestly there are so many thoughts and opinions to your questions it is hard to answer.
The best advise I can offer is to read around the forum and try and narrow down what would work best for you.
Also, there are a bunch of members in AZ. motorized bicycle folks are great to hang out with and love helping new folks. So finding a ride/rally or just a member nearby would be of great help. There is an events section.
Best of luck and I am looking forward to seeing your build!