Cost for a rebuilt G52 is around $1k changeover... watch the forsale section, they quit often come around from people buying donor cars etc and you can pick them up for ~$300. Terrain tamer rebuild kits are bout $300 pus the labour to have someone do it for, cheaper if u pull it out for them. While your there, budget on $300 in parts to do the clutch and rear main and save the hassle later on.
Alternatively, Marks 4WD do a complete Dyna trcuk box changeover, but its $2.5k, but youll never have to worry about destroying a box again.
For something in the middle, chase down a R151f from a turbo diesel bundera, surf, or hilux and you can make these fit. Price should be around $2k fitted.
If your keen, try Halls 4x4, [1 Barry Street, Bayswater VIC 3153] [Phone: 03 9729 7566] [Fax: 03 9738 1392] or All Toy Spares in Coolaroo Ph: (03) 9309 3333, or Marks 4WD 9702 7366 in dandenong.
============
Just on another note mate, coming back 3hrs later and saying "come on someone" isnt normally liked round here... most people work during the day and jump on at night... so wait a day before 'bumping' your own posts if no one replies.