obligatory battlebots 5 comment
I recommend checking this page out:http://beetlebros.gametechmods.com/ra2techs.htmIt'll help you improve your building skills.
much empty space. Is it invertible?
For the other botUse HPZsyou need one black for this Shrink the chassis as low as possibleuse shinniesput Irons on the disk if you want a disk type, or use a Tri-bar.
You should replace disc of doom's disc with a tribar and dual razors/irons.
You could also put in 4 HP zteks and there's plenty of room for two black batteries.