Those seats look real good in there. There's a guy locally that has tons of datsun parts. I'm going to check with him to see if he has a good set.
FYI you can get new upholstery from MSA for less than $300 a pair, and they are pretty good quality. Not too tough to install either. So if you find some rough ones, you can recover them and have like new seats on the cheap.
A few questions: what's the torque specs for the inner and outer tie rods and the ball joints?
I don't think they really have a torque spec? If you're using the cotter pins, just get them as tight as you can with a ratchet and you'll be fine.
How much should i take off of the spring perch? Obviously enough for the strut to go through. Here's a pic of how I've cut them so far. Which is best? I have a welder so I can fix them if I've messed it up.
Assume you're cutting the 1200 perch to fit inside the 280ZX perch? If so, you're fine.
As long as you have at least an inch or so all the way around it will hold the spring. You can cut it down to just a giant donut, or leave it as is. You don't have to weld it in, but it is nice piece of mind.
Another way we've done it is to find a piece of pipe with an ID just bigger than the spring, cut a 1" tall slice out of it, and weld that in.