How far into this have you looked? I tried several sorces and the best I could do was nearly retail price unless I bought a 20' container full....I don't have 70 grand.
What are the six places you've found? How much per kit?
The first link from Livefastmotors would be safe to do business with.
I am dismayed that a link to ReVoLuTiOn MotOrS is offered His latest offense is sending a smaller displacement kit, for example charging for a 67 cc and sending a 48 cc kit.