thanks a lot for your ideas, I like the Head and Tail lights a little more than the bloodfins and they are a little less of a bioload than the bloodfin.
you are right for the serpae, and the ember look cool too but maybe to small as I don't want an accent fish for this tank, I like the fact they will stay mid to top as the bottom is occupied.

I am thinking a school of 15 either serpae or Head and Tail lights (the lfs I intend to go has them both)?
Would that be reasonable to add 5 or 6 mandarin shrimp with the corys or too much competition?