Just Mark,
The 350 engine should work well with a cast iron bell housing. I have several that keep accumulating in my shop. The clutch fork opening is on the driver's side.
I have been happy with the mechanical clutch linkage in my 1965. I have no idea how easy your frame mounted clutch linkage will work with the 350 and bell.
Unless your T5 has seen low mileage and tender care, I highly recommend that you open it up and clean it. Then change the input shaft to a 10 spline Jeep shaft with a new input shaft bearing. Then get the end play set to zero. I am self taught and did not find my first attempt to be difficult. YOU CAN DO IT. Especially since I can help every step of the way.
The cost of an adapter plate plus the 14 spline clutch package will cost almost 3 times the cost of a Jeep input shaft swap. That's just my vote.
As for the braking system, I'll bet 52Carl knows the answers. I think he's done this once with a T5.
Jay