Follow up...
Thank you all for your input! I really appreciate it.
So I looked into transmission shops in my area because I didn't want to have the guy fix it who gave me the BAD advise to go ahead and drive it while the OD light was flashing, and knew what the problem was.
I went with a local owner-operator kind of shop. He quoted me the same price for him to rebuild it as a reman would cost. Then he recommended some options, which is what many of you did on the site here.
He has a lot of years in the trans business, so I felt good about the choice.
In the end it got the full rebuild with a shift kit and a billet converter. I've been driving it for a few days now and the shifting is noticeably different, but not dramatic. At least I know that the guy who did the work is an individual who knows transmissions and who I can go back to any time.
Thanks again for the help.
Nick