I thought about a line lock but I had several people tell me that they would quickly blow out the slave cylinders because they aren't made to handle pressure for a long period of time.
Not really neccesary to hold for a long amount of time, but at times you will need/want them. I don't totally agree with the blow out statement, I've been using mine for about a year and a half, I have left it locked for almost 2 months during a repair in my shop. I actually forgot it was locked and couldn't figure out why the Jeep wouldn't move the first time I tried to move it after the repairs. So 2 month's later, brakes still locked, no blown parts. I always tow with them locked also.
Mike, it aint real hard to install, just cut the line, do a double flare on each side that you cut, route the line coming in from the M/C into it, and route the line coming out of the lock back into your line you cut going to the brakes.