Protip: Even 9/9 gunners and standard BVE will cap relativly early with KM. The ONLY benefit to getting elite gunners for KM main gunners is to cap early in blitz where KM spread is most frustrating. If you are looking ahead then you will deal with it and use your range to make spread a non issue.
My 10/10 km gunners were just the same as elites of the same level after maybe the mid 70s.
And as for AA gunners if you want a good spread later listen to mako. Even on H44 my 100 vet level 116 aa gunners have garbage spread. However some people like that some people dont.
Also KM rep rate is crap because of having chief engineers that will have low repair ability so every little bit of repair ability on other sailors helps. If you are really worried about it you can consider doing something along these lines with your scout even:
http://www.opennavyfield.com/smf/index.php?topic=438.0