I usually run a 16 x 8 on my 25cc engines, but a Cub would most probably fly better on an 18 x 6. Using onboard glow power is optional. They usually idle slower and more reliably than a spark ignition engine, even without glow power. If you want to use onboard glow, I would suggest one of the "C" size 4000 mah Nimh batteries from www.cheapbatterypacks.com. They are only around 5 bucks, and will run full time glow for over an hour. If you use an onboard glow driver that cuts off the glow power above say, 1/4 throttle, the onboard battery would last for hours probably. But once again, that is optional, as they work pretty well without onboard glow power.

Good luck, and sorry about your divorce.... I am going through the same thing. []

AV8TOR