As far as Top Loaders go, I've heard, researched and considered at one time, for a different vehicle, buying a David Kee Top Loader. It's been a few years but that seems like the more "fun" option. I say fun because, I once was able to drive one of my still best friends, '67 fastback with an outrageous "beater motor" 351C 4V coupled to a Top Loader. Took it back to my house, because I was closer and had a floor jack, while he was at the shop and tighten the shifter so we could go "cruising" that night. Fun was an understatement. Yeah, I promised to not put my foot into it because of the loose shifter but I didn't promise to not do the same once I tightened the bolts. Well? just down the block I stood on it and let's just say there are very few things that feel or felt that great. That said, out of all the vehicles I've driven or owned, the 4spd. Mustang is my "Elenore or Unicorn".
While I do "get" the idea of newer tech transmissions in our older cars, the idea of swapping them out in place of a Top Loader is somewhat foreign to me. I mean, if I could convert my FMX to a Top Loader, I'd have all the parts in the garage right now waiting to be installed when the time comes. Don't think I haven't looked into it a couple hundred times since we bought the vert in 2021. The caveat here is, it will always remain out of reach since the pedal brace is non-existent, with most having already been recycled for the 4th generation as a Maytag or, if you can find one, the price that it commands requires a second mortgage.
Please don't get me wrong. New tech or newer than 1973 can do some great things for our cars. I'm not the purist that wants a concourse ready car, just one that has some of the bells and whistles that were available but not installed or maybe installed and pirated over time. Mixing parts or components in the years from 1967-1973 isn't off the table either. Yet, in the end, it has to be a personal choice, and I'll freely admit I can respect and applaud some of the "improvements" many have made here.