Cool bike (if I posted the right pic), but it is not good choice for your first build.
A 20 inch bike like that makes it difficult to mount and adjust everything.
I think the 2 stroke China kits fit without an aftermarket intake, if you have a small air cleaner.
Unless you have a lot of mechanical experience, I would build a beach cruiser first.
You can put a banana seat and apes on the cruiser, or you can transplant the kit to the Prince after you get some experience.