Simple answer, get another engine.
Long answer, lot of money, starter, solenoid, adding a charging circuit, etc..... Probably a few hundred dollars at least.
Go with the Honda Clone, you can find them with the electric start for around $399 more or less.
Harbor Freight has a 2 year unconditional warranty for about $75 so if/when it goes out, just take it in and they give you a new one.