Paint-matched Line-X is really expensive. I dont think its necessary, but it all depends on the "theme" of your rig. I definitely like how mine turned out, but its not on the exterior other than the wear-points and its black which is what all my color accents are. Just to give you an idea...inside the tub--all the way up the firewall, out the door openings covering the rockers and folllowing the bottom of the door line on the rear fender, kicking up slightly at the back of the rear fender line on around the back. That line is matched on the lower tailgate at the bottom...as well as the 'inside the tub face of the tub. The liner continues over the bedrail to the radius of the fender (for good step and top installation protection. The entire underside of the tub is lined including all under faces of the rear fender-walls, the core support, the engine compartment, the inner fenders. The inside for the front fenders, door panels were also lined...for $1800. Its alot of $, but its alot of Bronco to have to coat and alot of protection.
There can be some fitment issues with front fenders--you can see how I addressed this in one of the pics in the attached thread, and a few other areas that you need to be aware of and make sure they are taped and removed so that you can mount the fenders, but its pretty obvious if you really look at how the pieces mate. It could be easy to overlook however.
Here is a link to another thread where I posted some pics. They are not the best pics and they dont really do alot of justice, but they give you an idea.
http://classicbroncos.com/forums/showthread.php?t=113074&highlight=Line-x+underside+pics
As said above, unless you are going for a real 'Road Warrior' vibe, coating the whole exterior with any bedliner, while gutsy is probably unnecessary and could pose problems for repairs later....hell, I worry abotu that with what I hve now, but I think it will hold up pretty good...and mine isnt for show. If you do go for the full coating, spend the money, get a really well-experience Line-X shop to do the work and have the Kevlar with UV protection upgraded formula (Line-X extra or plus or something) in the color of your choice sprayed...your jaw will drop on the cost, however, it will give you the longest lasting and 'stylish' (in the sense of fade-resistant color) of bedlined finishes. Otherwise, fading is definitely a concern. Sicking with a good paint job should allow you to buff out scratches and fix minor blems easily, however...just make sure whatever you do that you start witha good foundation and solid sheetmetal...the bedlining is a durable alternative to undercoating, but its also more permanent...you really need to be sure that as you send it in that its in its final body-work stage of being...you dont want to have to cut, trim or alter anything after its sprayed...it stings. In other words do a pretty thorough mock-up before you have any bedlining done. Good luck.
John