Precision Gear has been quietly making clutch-type LSDs for all sorts of Nissan rear ends for a while now:
http://www.precisiongear.com/pgbrute.htm
Pricing:
TL54-3 H233 WITH DRUM BRAKES is $360 (33-spline only)
TL52-2 RC & C200 is $375 (out of stock)
LOM59-12 R200 WITH 12mm BOLTS (rear application) is $550 (out of stock)
R200 unit should be easily adapted to our R200A front housings.
C200 unit might be as well, AC's R200A ARB is a C200 unit.
They're in Michigan, if anyone in the area would be interested in donating their R200A front diff to 'em for a while so they can figure out what changes are needed to the R200/C200 units so they'll fit the R200A, that might come in handy. I'm going to talk to them some more to find out if they're even interested in investigating it.
Cool!
Brent