jrotor, I'm going to play devil's advocate to the good electric advice you're getting here. I fly both glow and electric, and for me, speed 400/480 is my practical cutoff. Above that, I've found that batteries, motors, and ESCs get too expensive......so I stick with IC engines in .15 and up range. But, I also have a TD .020 powered ship that was originally electric powered and lost over an ounce going from E power to G power--nearly anything can be powered by EITHER glow or electric if you plan carefully. If you're set on coverting the spree, I would recommend only one engine--the norvel .074. It's very reliable, fully throttleable, and weighs just about as much as a speed 400 motor. You can use a 400maH 1/2AAA Rx battery and a 6 gram throttle servo, thus potentially losing a fair bit of weight. If this sort of thing interests you, I suggest you do some research in the 1/2a forum--very friendly and innovative bunch of guys.

HOWEVER, since you've already got all the kit for electric power, I would suggest you follow Matt K.'s advice on the CBP 8 cells packs. Most of the 2/3A nimh cells are GREAT for speed 400 power, and provide a far better 'sport flying' value than spendy LiPos, in my humble opinion. I do use Lipos and brushless motors, but I think they're a bit of a luxury, rather than a necessity in most cases. Then again, I've seen Gary fly at NEAT and I know darn well he NEEDS the power to weight advantage these luxuries supply.