"With it mounted on the pump enclosure, sounds like you'll have a fairly long run of unprotected, high amperage wire."

Not necessarily.  If the battery, master solenoid, and pump breaker are all mounted behind the seats you can arrange the placement so that the master solenoid and pump breaker quite close to each other.  You can then use a short wire from the output of the master solenoid to the breaker.  That minimizes the amount of unprotected high current wiring.  If the pump and pump solenoids are also behind the seats you end up using very little high current (i.e. heavy) wire for the entire landing gear circuit.

If the master solenoid is located elsewhere then Bill has a very good point. You don't want to run a lot of unprotected 10 AWG wire.

Tom Gourley