advice on 5 speed swap, suspension mods on 60-66 panel truck

[Chuck78]

I'm dying to find a 60-66 2WD 1/2 ton panel truck project sometime in the next year or so. Looking for some advice on some modifications.
If I decide I want more than a 700R4 (od= must have), I was thinking of swapping in a 5 speed tranny. Some stronger T-5 models may do, but might need something beefier. I really liked the 1/2 ton version (MG5) of the NV3500 1988+ 85mm 5 speed, 4.01 1st and .73 od. Anyone ever swapped in one of these? I was wondering about trans tunnel clearance (probably fine?), shifter location (I guess it'd work fine), crossmember modifications (driveline angle is important), and most of all, the hydraulic clutch installation/fabrication/setup. I assume the input shaft would be the correct length, but haven't checked.
Anyone ever done at least a hydraulic clutch swap on any of these trucks? Tips, parts used, etc?

Secondly, really wanting something that drives nice and will haul. I was told that the whole front end of a 73-87 will bolt on. I liked the idea of more modern suspension geometry and steering. Not sure if swapping the a-arms from my 89 would have much if any effect of the suspension geometry, or even if this stuff would really swap (and make an improvement). I know 63+ had redesigned front suspension.

Wanting some heavier duty springs in case I do some towing, so spring advice is appreciated as well. Leafs I could figure out, any tips on rear coil sources for 3/4 ton payload would be appreciated. Don't want a monster truck, but don't want a sagging rear! Are coil rears as good as leafs for heavy duty use? I'm leaning towards a 63 or 64-66 GMC (GMC's came with leafs primarily, right?), but my options are open.

Lots more questions, but this will do for now. Glad I found this board!

Thanks,

Chuck