If you want to try and look for a used t-case locally you should check out
http://www.car-part.com/ . I bought my 14bolt rear axle from a place listed on there and got a pretty good deal. So its worth a shot to look.
I would suggest you get either a 208 to replace the one you have or a 205 which is a lot stronger that the 208.
NP 208
Type: Chain-driven, aluminum
Low-range ratio: 2.61:1
Weight (lb): 79
Lubricant: ATF
Length (in): 8.0 (GM); 15.5 (AMC)
Width (in.): 20.0
Height (in.): 5.0
Used by: Many full-size vehicles, including Jeep pickups and Wagoneers (which used a left-side front output shaft). A part-time unit that replaced the stronger, heavier NP 203, the NP 208 can't stand up to the horsepower that the NP 205 can, but failure is more often related to low oil level than too much input torque. The 'case utilized left- or right-side front output shafts. All Jeep model 208s have the same spline and output-shaft size and bolt pattern as the Dana 300.
NP 205
Type: Gear-driven, cast-iron
Low-range ratio: 1.98:1
Weight (lb.): 138
Lubricant: 80- to 90-weight
Length (in.): 13.0 (GM); 16.0 (IH)
Width (in.): 18.0
Height (in.): 12.0
Used by: 1971-1980 Broncos, Blazers, and Ramchargers (and corresponding full-size pickups); the NP 205 is still used on heavy Dodges. Some Dodge and IH models were longer, "divorce-mounted'' versions. The NP 205 has left- or right-side front outputs and a center rear output. Caution is advised: there were many varieties in NP 205 shaft splines and so forth. A PTO plate can be found on the left side of the 'case.