As I think if you want to destroy slavers and to be an IMG better make it like a strike group. Just fighters/bombers and maybe a few gunboats(like a HS.| was, they were the best anti slavers dudes).
Defend the bases if it needed and try to stop slavers.
And you don't need in any caps. More caps - more problems like asteroid fields, also you need in a shipyards to repair it and etc.