As others have said, the newer Wranglers do not have a steering wheel lock, so no need to turn the ignition on.
The odometer does not register miles when towing my Wrangler.
You can buy a nice plug-n-play tow vehicle wiring kit for the JKs for about $80 bucks. The wiring harness in the kits plugs into the tail light wiring, and contains diodes so that the towing vehicle will not back-feed the Wrangler's electrical system (other than the tail lights). So there is really no need to isolate the Wrangler's battery.
If you do want to install a battery isolation switch (say to prevent parasitic loads from draining your battery when the Jeep is being stored or not being used), you can pick one up at Harbor Freight for about five bucks what works fine. http://www.harborfreight.com/battery...tch-97853.html
Most supplemental braking systems for towed vehicles require electrical power, but the NSA Ready Brute tow bar which I have includes a mechanical surge brake that uses an aircraft cable to mechanically apply the Wrangler's brakes - thus no battery power needed and no big supplemental braking unit to install in the driver's floor every time I tow.
So with my setup, I just install the tow bar and safety cables between the tow vehicle and the Jeep, clip the aircraft cable brake line to the tow bar's surge brake, plug in the lights to the tow vehicle, put the Wrangler's manual transmission in gear (or automatic tranny in park) and shift the transfer case to neutral, and off I go with the Jeep key in my pocket. When I get where I am going, the Jeep's battery is in the same state of charge as when I started the trip.
Doesn't get any easier than that. Just remember to never try backing up with a toad attached!