RE: World Models Spit 80" Conversion ??'s
Larry,
I would recommend the lower wind 40-5 motor over the 40-6 motor because it will handle more current if you need it.
Hobby Lobby is looking into higher power controllers that provide capability beyond the Jeti 77-amp Opto. (Hint: Remember that Jeti makes the Hacker Master controller series)
I would not recommend using the Jeti 77-amp ESC on this application with a 10s Lithium power supply. Instead, I would use the Hacker Master 90-O-Acro or wait to see what Hobby Lobby offers soon.
As for Lithium cells, the new Kokam 3.2AH (20C) cell will be hard to beat and the packs will be the safest on the market.
Good luck!