Bulkheads for a 60 gallon cube.

[BCOrchidGuy]

My drill bit measures 1 1/4 inch diameter, what size bulkhead do I buy to go with that. I used it before but for the life of me I can't remember which one I used. I'm planning on running a Mag 7 or maybe just a Mag 5 for the return so I believe one bulkhead/hole will be enough but am considering two holes just incase one gets plugged. I'll use Seios for flow in the tank but want the sump for auto top off etc...

Doug