My transmission is going out.

[Chamberpains]

Get rid of that stupid needless coolant cooled trans cooler. Its more of a trans warmer than anything else. Coolant is always hotter than ambient air.
Go with the weller reman. Its already done and ready to go in when it arrives. Your guy starts tearing in and finding individual parts that need replaced and ordering them, thats where the problems start. They start showing up at different times or if they're on back oreder for weeks. Don't chance it. Get back up and running sooner.