R180, R200 LSD's and parts Interchangability

I'm gearing up to build a turbo rotary powered Triumph Spitfire. I plan on using a Nissan/Datsun diff because: 1.) It's strong (the R200 more so than the R180), and 2.) It's narrow. A Mazda diff requires that you fabricate short axles to fit between the flange on the diff and the flange at the wheel bearing carrier. I think that with the Nissan diff and a set of adapters, I should be able to make Miata axles work. I am not looking to make monster hp with the Mazda motor. I'm thinking just some minor tweaks so that I can make in the neighborhood of 250 hp. Also, and the car is extremely light, but I do plan on auto-x ing the car with sticky tires. Most likely Kumho V710's... or alternatively, what ever I have lying around or can find cheap. On the street the car will run street tires, but on the track, its to be stickies only, so the diff needs to be fairly strong. A Miata diff would not do. A welded diff is out of the question because this will be a dual purpose car; street/track. I have done some searching on the forum and many of my questions have been answered. There are several that have not been adressed though.

1a.) Are there 240sx's that had LSD's in them?
b.)if so, what years?
c.)what types (viscous, clutch type, helical)
d.)R180 or R200?
2a.) What years and models of the early Z's had LSD's?
b.)what types (viscous, clutch type, helical)
3a.) What parts are interchangeable between diffs?
b.)Which diffs have short pinion shafts? which ones have long pininon shafts? Are there more than 2 pinion lengths for LSD diffs?
c.)can the limited slip unit from one diff be swapped into another?
4.)which cars have a 3.7:1 or 3.8:1 ratio ring and pinion that will accept a LSD unit?

I know I know, thats a lot of questions. Sorry for that. Any help is appreciated though.

R33 GTS-T Skyline has an R200 and they are very cheap. They are also less than 10yrs old so they are easy to find and plenty of aftermarket support.

All R200 casings can have internal parts interchanged.

I'm planning on puttng this diff into a car that could seriously benefit from having a narow rear end. Are the late model diffs (300Z, 240sx, R34 etc) wider than the early model ones (240Z, 260Z, 280Z, 510 etc)? Any one have any idea how much the difference might be if there is one? Also, which models are likely to have a gear ratio close to 3.8:1 or 3.7:1. I have noticed that it is pretty common to find old Datsun R180 diffs with 3.7's in them. I think that was something that was the automatic cars. It looks like the open diffs can be converted to lsd by unbolting the ring gear from the spider gears and substituting the lsd unit, so thats good.