hmm...a 4 pointed spoke. Definitely would make maintenance easier and all areas would be accessible. Not ideal for space conservation, but I think the trade-off is sweet.
I think the junction point will need major power connections, switches, various reaction media and chambers, etc. Having that many tanks pour into one - it would probably be one hell of a sump space. A drum would probably not work (just my opinion).
What about a refugium under each trough that was higher than the input to the sump to use gravity to work that through? I am just tossing out ideas here as the nature of your question seemed to be open ended - was not sure how you were going to handle that piece.