Yes for power reserve!I think you need the power reserve in case the wind comes up.
Also, the safest route prop-wise is to stick to what is already there.
I think a pair of HPEVS AC-9's could be the ticket.
old prop can be a start when you don't know your motor characteristics, then adjust until right.
old prop usually means you need a big rpm reduction (you'll need that anyway in most situations).