Between the Auburn and Truetrac LSDs, I'd definitely go for the Truetrac. The benefit to the Truetrac is that it is especially well suited for snow and ice conditions since it is a gear-based LSD which does not have the tendency to cause slippage on ice that a clutch-based LSD can. The Truetrac drives totally like an open axle until enough RPM difference develops between the L-R sides which then causes it to go into action. Wheras a clutch-based LSD couples the L-R sides together up to a point where they overcome the clutch so the differential can "differentiate" and allow the tires to rotate at different RPMs which is required when turning corners.
But again, you will need to have the backlash adjusted for any full-carrier device like the Truetrac.