After a few hours reading this morning, after not being able to fall back to sleep, I have decided to go with the 530 chain from mfg supply, the tensile strength is 9790, most of the #50 I've been able to find specs for were in the 6-7000# range. I also found a thread where kghills mentioned his pin counts as follows-
86 t20 to pizza pans
118 fronts
112 rears
Sound about right? These are all lengths mfg sells pre cut so that makes life a tad easier.
Still leaning toward snap idle tensioners, the only issue I can see, since removing the factory tensioners is the square cross members may stop them from from moving close to the sprocket when changing direction. Or do the snap idles pretty much stay put when adjusted? Has anyone tried the snap idle concept but instead of the side straps use eye bolts and heavy springs to keep constant tension? In my mind it would be like a cheap redneck centaur tensioner where it would have tension on either side so changing direction wouldn't add stress to the tensioner when the slack side changes. Or the springs would at least allow it to absorb (some of) the shock rather then just busting off the studs or wallering out the bolt holes in the straps.
Edit- rain rain go away, I got some welding todo today....