If you haven't gotten the solenoid pack to install yourself and are planning to have a shop do it, you may want to check with other shops since the remans are still available.
Yes, most of the online Mopar shops are out of the NOS solenoid packs, but it may be worth it to have a local Dodge/Chrysler dealer do their system search. However, decent transmission shops (location links below) use several reman transmission parts suppliers in the US and Canada that likely have the solenoid packs (as well as most of the other 42LE/A606 parts). See photos below of one of the reman solenoid packs I got a while back on sale - reman p/n 62420 or 62420R may be a standard number (haven't had need to install it yet). And if the shop told you that they can't be rebuilt, that is obviously incorrect. Of course the reman suppliers do it with the kits I show below (TransTec & Sonnax). It takes careful work with the little fiddly parts, so most shops will just get a reman solenoid pack and return the core to their supplier. Obviously, if you have the shop do it, you want them to order the part so they will give you a warranty on it. Getting a reman off ebay rather than a known transmission parts supplier can obviously be hit or miss. When I researched this a while back, there were some trans parts suppliers online (most associated with TranStar, TransTec and Sonnax) that would also sell retail to do-it-yourselfers, but I didn't keep a list.
For trans work it is best to go to an independed ATRA certified shop (do not go to chain shops like AAMCO - terrible). ATRA certified shops are in the US and Canada. Other independent ATRA shops will honor the warranty from a member shop.
ATRA - Automatic Transmission Rebuilders Association

Or check Western Canada Chapter site or call 604 254-6288 to see if they can refer you in the east.
ATRA Western Canada Chapter
Here are photos of the reman solenoid, gasket/screen (from an online Mopar dealer), TransTec & Sonnax rebuild parts. The top sticker on the TransTec rebuilt kit shown below says A604, but the Transtec bag label says A604/A606 so it works for both.