I was considering the Blast due to the availability of them which I have noticed almost every metropolitan area has at least one or two, some areas I have seen 8 for sale! and often for very cheap, roughly $1700 running, or about $700 or less not running.
Also, after getting to ride my friends Zero ZF9 with a belt drive I have realized the huge advantage, no lubricating, no mess, completely silent, more efficient, its truly the way to go! and to have the ability to produce these parts myself I could make it a realistic possibility to convert these bikes much easier.
I would consider other motorcycles for conversion kits as well, but I think I may start with the Blast and work my way from there, If I were to produce motor mount kits for other bikes what would you want, Ninja 250R, Suzuki Katana, Gsxr...?