I was planning to install a cut-off switch to prevent vandals from activating the winch at the contacts, as I have heard stories of. I bought a Blue Sea 6006
http://bluesea.com/products/6006
Since then I have run across the idea of mounting the solenoid box in the engine compartment, but haven't looked into it further than that yet...
Definately remote mount the solenoid box. With the solenoid box not accessable, the winch cannot be energized. You won't need a cutoff switch, the solenoid box IS the cutoff switch.
On a regular setup, the wires that are supplied will work fine. With longer wires, it's almost always a good idea to go bigger.
When you install interior winch controls, be sure to have a master switch so that you cannot accidentally engage the winch from inside. The two-switch interlock system also helps prevent accidental use by children(!) and other people with busy fingers.
Mine is controlled two ways:
1. ignition must be on (engine does not have to be running, but it's a good idea)
2. master switch
My winch controls are on the left, by the window, so that they're reachable from outside the vehicle as well, and not likely to be pushed by my passengers looking for heater controls and stuff.
I'm not a fan of toggle switches, they're too easy to accidentally actuate. That's why aircraft have those fancy red covers....
Good luck, and have fun with your installation!
- Brian