All hope is not lost haha.

How fast do you want to go? A very popular electric setrup (for good reason) is running a Leopard motor, with perhaps a fightercat or Castle Hydra esc are popular choices. Brushed motors won't be feasable at all for a 69 inch hull. To get good run times, your going to need a parrelel battery connector, which makes it so two batteries equal the voltage of one, but it gives you twice the amount of run time. It's expensive, but if you want runtime it's what you have to do.

A good setup would be:

Single or twin 730Kv Leopard 5692 motors

Single or twin castle hydra HV 240amp esc's

4 12s batteries (two will be run parrelel)

This will be a heck of alot of power, now that I think about it 10s or 8s in parrel will be more manageable.

Also regarding brushed vs brushless, brushed may take less power but they are far less efficent.