1. Any e36 pedal box will work
2. The only wiring required is to wire the auto trans selector to think it’s in neutral or park so you can start it if you’re not reflashing the ecu, And for the reverse switch, but is super easy and many how-to’s around. I did have issues with rev hang and stalling when cold pulling up to an intersection, which was solved with a manual ecu.
3, No fab work required.
From memory there are two different types of clutch masters with different fittings on them for the hard line, so be weary of that if replacing with new.
There’s a 4 cylinder and 6 cylinder shift linkage, the 6 being 20mm-ish shorter, but can cut and weld the 4, or just get a DSSR.
Also need the front half of the drive shaft as is a different length to the auto, and I think is different between a getrag 220 and the zf, the zf being the stronger box correct to a 328i, but 220 is more common being fitted to the 325i and down.
Are also two different sized guibos (driveshaft couplers) so check for the right one of getting a new one.
Oh, and some 4 cylinder drive shafts have a balancer on the front which fowls the shifter linkage and needs removed.
think that’s about it. Definitely worth doing looking at the price of manual big 6 e36s currently, and even better if going from a horrid jatco auto!