Jim...
I'm a tech-head myself but also a firm believer in the K.I.S.S. principal. Video rear vision is a neat concept in theory but will come up short in reality, largely because video is pretty low resolution, loses a lot of the depth cues because of the single camera lens, is subject to getting dirt/mud/water on the lens, and is just plain complex. Properly mounted and sized towing mirrors are, IMHO, a far, far, far better solution than a complex video system. For one thing, they extend far enough out from the side of the vehicle to give you some vision of what's immediately behind your trailer and the ability to properly estimate how much clearance there is between the rear of your trailer and a vehicle in the lane you want to move into. You are simply not going to get this perspective from a roof mounted camera.
'Tis true that the stock mirrors on your Liberty are useless for towing a moderately wide trailer like a TM...the stock mirrors on my old Cherokee (about the same width as your Liberty) were equally useless.
But, like many here, I solved
all of my rear vision problems when towing by getting
a pair of strap-on Mckesh towing mirrors . Once you get them adjusted, they go on and off in about 15 seconds, do
not mar the paint and do
not vibrate. I ordered the optional convex mirrors with mine and find they really remove all blind spots. McKesh mirrors are the gold standard for maximizing your rear vision, particularly on SUVs and other vehicles you don't want to permanently mount large towing mirrors on.
EDIT: Added: Most states have laws that clearly specify mirrors for rear vision (see this
camping world article (about the Mckesh mirror) for specifics of each state) . So even if you do manage to rig a workable rearview video system, you're still very likely to eventually get ticketed for not complying with the requirement to have suitable rearvision
mirrors.