@TFerguson both of these options are the real deal if you got the coin.
It's not in either of my squares, but I have a 200-4R from Bowtie Overdrives in my '79 Camaro. Giving it an extra gear over the TH350 was the best thing I've ever done to the car. It's been doing great for over a decade (14 years I think). I never had any issues with it, and their setup procedures are good. We recorded pressures in each gear and ran the first test drive with a pressure gauge on it. I used their TV made EZ cable kit. Factory square stuff should be a lot easier to set up and adjust.
My dad has a 200-4R from Jake in his '80 Camaro. He got that after his Craigslist unit took a s**t. That might've been caused by a bad TV cable, but we never took it apart to figure out what went wrong and I honestly don't remember how it failed him. Anyway, Jake's transmission is doing great in his car. Jake used to be very active on the Camaro forum, and is still very well respected over there.
I think Viktor is right. My old man told me that Jake was mostly doing 4l80e stuff now.
^^^ This is the most important point of them all.