If you're up for a drive, check out these folks. Rocky Mountain Truck (LLC) in Great Falls, Montana. 406 452 8561 John H. and John R. are the owners, (not related)
I bought my 96 dodge from "little John" years back (his personal rig). Straight forward and as honest as I think you'll find, bar none. I have yet to meet a single person that has anything bad to say about their shop. Most make it a point to praise their satisfaction with their service. They are factory trained cummins and Detroit service techs as well.
They will rebuild your existing transmission with all the upgraded parts to make it last another roll of the speedo or better.
If you want brand new, drop my old boss a call at Autoworld hi lo truck shop in Great Falls 406 727 8915. Owners name is Kenny, he'll treat you right. (not to mention NO SALES TAX in Montana

It may be enough to justify the sale of a new one for you. He also sells NV-5600 conversion kits for the nv-4500 equipped trucks.
Montana is a nice place to visit if you haven't been there yet.
Wish I was there right now, Alabama is a hard adjustment coming from Montana. (we're stationed at Maxwell AFB now).
Tell them Dave K referred you and wish them well for me.