A 93 model is 4L60-E Not a 700r4. Same trans, but one is Electronic one is not. You won't be using an Electronic one in that truck. IF you choose to go 700r4, look for an 88-92 preffered. 87 is OK, but 86 and older you should avoid. There were improvements made every single year on the 700r4, so the later the better, but the 88-92 to have the stronger shafts.
I'd avoid the 200-4r. Big Big Bucks to make them worthy. Art Carr does it. The 200-4r is the 700r4 Alternaive for Buick, Olds, Pont, Cad that want to run a rear wheel drive Overdrive trans. Being that 700r4 does not come in that bellshousing. 200-4r is a universal bellhousing and will fit all + Chevy included.
That T400 with B&M stuff and 2000 stall does sound like a real good deal. It'll sure bolt in there. The short shaft is the one you want. The long shafts were for long boat large full size cars and vans. Trucks got short tailshaft with 2 piece driveshafts and that's why the yoke is bolt on for trucks. But you can use the car yoke too if the U joints fits your drive shaft, but you're likely to need to get a special u joint. If the output shaft is threaded for a bolt on yoke, then your home free, no special U joint needed. The speical U joints really aren't that expensive. Maybe $25 or so and only good quality companies make them.