I only have moto-east to reference and I'd recommend them from my experiences to date. I also daily quakertown through KOP to exton so Im glad to hear some Montgomey County love up in here.
I also bought a used 86 and I have had the same questions about my gearbox but I've changed the oil to motoul (from moto-east
and its feeling a little better now. Not tremendously but good enough that I don't worry anymore. I was thinking about changing the bushings too since I've seen it a bunch of times working on the exhaust.