I used one 4 cell 4000mAh Li-ion pack from Bern Furgang. It has two sets of cells in series and then in two parallel pairs. I also have two leads coming from the pack . Both leads are common to both pairs. The switch has two input leads to share the load on teh connectors Its light and sort of a back-up system, but is really just a parallel system..

Yes, I used the pull-pull. Kept the rudder servo as low as possible. Used an 8611 on rudder and 8411's on elevators.

Wheels are 3" from Dave Patrick Ultimate. Nice and narrow and light.

Hope this answers your questions?