Just 'casue no-one said this: I reccommend a stock t-case. (I'm aware ofthe 2F resolution, just speakin' for the heck of it.) Unless you're planning on climbing trees or cliffs with your rig, a stock T/C is great, it fits right, has both gears you need (high/low), and are relatively tough. No matter what case you go for, (NP235/208, Atlas 2 sp), they all have two speeds, sure the gearing's all different, but I say, semantics! Unless you really need a crawling box, a stock t-case will get you anywhere you need four wheel drive.
As far as transmission goes, I've spent my life in or around Chevy pickups, and will gladly advocate an SM420/465, but since we were dealing with a Ford engine, Borg Warner makes some fine gearboxes, like the T-18.