I use Castle Creations ESCs
http://www.castlecreations.com/produ...nderbirds.html I use the 9A for my little guys.
I prefer to stick to 1 pack size, to keep things simple. If you do decide to go with different packs, don't forget that your CG will change unless the pack is right on the CG. I use 850mAh in my little electrics.
I don't care much for most of the super light coverings, but I do use them to save weight. One I do really like though is Micafilm. It doesn't have much stretch or shrink, but it looks like tissue, is very light and is stronger than Monokote type coverings. It has no glue backing and the instructions say to use Balsarite, but I found that using a light coat of 3M77, letting it dry and then ironing it on works fantastic.
This little plane is covered with Micafilm.