I did the DCC conversion on my S14. Some of my work and research should be useable here as well....

As for the sunload sensors, ambient temp sensor, and cabin temp sensor...
U13 Altimas (1st Gen) had optional DCC. All of the sensors from this car work. I think it's GLE trim level only.
89-94 Maxima had option DCC, and all the sensors work.
All J30's have DCC, and have the same sensors as above. These are much easier to find.

About the cabin temp sensor, there is an air fitting and tube that goes with the sensor to suck air across it. Mine works fine without that contraption, with it located at the lower edge of the dash.

About the ambient air temp sensor, it's supposed to go on a bracket in front of the radiator. It was too much of a PITA to run wires all the way out there, so I just mounted it in the driver's wheel well, right off the main harness.

The S14 DCC has a diagnostics mode. You should see if the S13 one does, too. It's certainly helpful.

S14's have all of the automated door motors stock. You might check to see if they're compatible with S13 stuff.