I assume you need a psd case?
if so, check into going with a d300. You already mentioned upgrading the low range. The 300 has 2.62 with as low as 4:1 available. Its also a very common swap to those transmissions so I believe the adapters will be considerably cheaper.
77 CJ-7- AMC 360, Edelbrock cam, MC2100, Fenderwells, CJ T18/D20, Chevy D44/EB 9" rear, Trutrac f/r, 4.11, SOA, 1.25 lift shackles, 35x12.50 BFG KM2s, Shackle Reversal