I think -10 would be the closest equivaalent. Get ready to pay up, and deffinitely measure 2x and cut once I don't know how you were planing on doing it, but I'd take a lot of measurements, buy your hose in bulk and custom fit each hose for its location. You insert your NPT to AN fittings on the motor/inlet/exhaust, put the AN hose end on the hose and tighten onto one side of the runs NPT/AN fitting, then mock the hose the the other end. Take out the correct amount of hose for the other hose end, then pull the hose off the boat, cut, install other hose end, and repeat for every line you want to replace. This way you are only cutting off the bulk of hose and not wasting any.
To cut the braided, you can use a big chisel on flat concrete, or a bandsaw, or a chop saw. You'll want to use tape (I use electrical) at the incision point to minimize the fraying. Hopefully you have a simple coolling system and it wont cost ya too much.
Good luck,
Chris