You might try a rebuild in place. A rebuild in place (actually it’s more like spread all over a garage floor or bench) involves taking your current tranmsmission apart, picking out the good pieces of that can be reused, adding the kits that need to be added, putting it back together and buttoning it up.
This might seem like the way to go in your case, but, think about this. The clutch packs require major disassembly work to reach and if they are gone, it is likely that your bands are gone. In this case, the solenoids that cause it to work correctly will also likely have to be replaced, just to be on the safe side. These are just a few of the major assemblies that interact directly with the clutch packs to enable your transmission to shift. Given that parts of the valve body may also have to be replaced, including, probably more than one check-valve, you are already looking at what is essentially replacing the transmission with nearly all new parts. And, you are also looking at a huge, unneeded, expense. The expense of finding, purchasing and replacing the parts that have failed as part of the rebuild is the same as if you had replaced the transmission in the first place.
You could, on the other hand, try to locate a used transmission at a salvage yard from another vehicle that is similar to yours. The key problem with this is that you won’t know the condition of the replacement transmission until you have it put into your vehicle. You might be lucky and it could work correctly for years. In this case, you will have saved between $1,000 and $1,500.
On the other hand, if the replacement needs work itself, then you could be out that much again and you still won’t have a repaired transmission.
The only real solution — you might not want to hear this but it’s true — is to bite the bullet and have the transmission replaced. Though it will cost about $2,800 or $3,000, it is the only way you can be sure your vehicle will run well when the repairs are finished.