You want to do air combat, I recommend buying the heavy plasma guns for as many bikes as you can jam them on and lasers for the rest.

Heavy plasma does the best damage overall for tech you can fit on a bike, and it saves on logistical effort to avoid the various types of missile launcher. If you run low on E, you can steal some from solmine. I recommend stun raids, but it's your call if you want to escalate to full on war.