Man, I bought a 77 j10 way back as a parts rig for my wagoneer - it too was a levi's edition with the same purple paint!! I initially liked the middle color too, but I think the lighter one would blend in, or flow with interior better - for lack of a better way to put it. If you could get a floor mat sized sample it would help visualize better how it would all look. Also remember - dark hides the stains, but light hides the dirt.
As for the door seals, rockauto has a bunch of different profiles under the universal parts section - listed under trim molding/trim seal.
https://www.rockauto.com/en/tools/body+ ... al,1000202
They list the dimensions which is helpful if you have your originals to match up.
The issue with universal seals isn't the joining of the the ends as much as wrong dimensions/thickness/softness IMO. The crutial pinch area at least on my 73 is the rear section from the bottom up past the latch area to the bottom of the window. It is tighter there than anywhere else - by alot. Too thick of a seal can't compress enough to close the door easily. However, the bottom and to some extent the top areas have a much wider clearance, so the seal bulb needs to be large enough to fill that. For the tight areas, the actual diameter of the bulb isn't as crucial as the compressed measurement - which is all about the thickness of the rubber and the windlace that goes on the pinch weld. I'm betting that the factory seals are made of thinner rubber and have thinner windlace to compensate for the narrow area up along the door latch area. Just a guess.