Regular 3/4 oz weight. Use a floating crankbait so when you stop pulling it will float back up. You really dont need a bait that runs more than the length of your leader. Try to stay in contact with the rig the bite is either a rip your rod out of hand deal or pick up and hes there.
If you dont use the boat very often and fuel cost/use is not a big issue I would go with the EFI. Here is why. I think that the Optis are somewhat of a sensitive motor and sitting up or runny low end oil and gas through them is something they dont like. Both motors are great but that is my take on your situation.