I had a new solenoid last about a week. I think they make the classic looking ones out of defective chocolate. The solenoid on the high torque starter will be reliable.
I have used the rubber exhaust mounts as junction points for all of the wires when removing the solenoid from a car that originally had an inner fender mounted solenoid, you can also buy an insulated stud at automotive wiring suppliers that does the same job. While a solenoid is basically a relay for high amperage, the job of triggering the solenoid on the high torque starter will be done reliably for years with a modern waterproof relay, like ones available from Hella.
Whatever you do, take some time to fit caps and boots over large diameter wires. Pay attention to how all wires are routed. Ask yourself where these wires will be in the event of an accident.