"what I am looking for is good fighters and DBs"

Based on this, you just described KM. If you can overlook the fact that you have
longer grinds between CVs, then KM has both of the things you want. Also, the
europa can fit 11" singles iirc... >:D

IJN has lots of cvs's that keep you interested and ease those long grinds...they have decent hitting DBS and
fast fighters too

KM has very good fighters (the best I think) and hard hitting DBS...downside is they only have 4 cvs

UK is what I have but they are known for awsome TBS (better than DBS IMO) and supposedly have the worst
fighters although I don't notice

MN has really good bombers for the next few weeks and average fighters

Their Fighters got buffed up in the CV Patch (T3's with T4 Speed anyone?) MN is
supposed to be 'balanced' after SN comes out,the bombers are supposed to be getting
the nerf stick,not sure if the fighters will be touched.

If anything,wait and see how things turn out.

if you want good DBs, go MN. They have the best DBs currently (although they may be nerfed
in the future) That's just my opinion though, see what others have to say. I'm not too
sure on the fighters, check some of the CV threads in the MN section of the forums