get elite acc gunners, but class them as reload gunners when the time comes. BVE'd they will hit both caps around the time you are in a BB3.
you could run 5 engie/5 rep. however myself I like to run 6 engie / 4 rep. Heck 7eng/3reps would give you massive overheat and still hit the repair cap eventually...done right :) I dont like elite engies myself as they only have a +9Rep stat. i prefer to use +12 engies with +11rep stats.
Potential and a scout is all you need. AA gunners are an option, few people use them. However if you decide to level a pair leave them as Armament sailors as long as you can.