I was in a similar situation to you when I was first deciding which supra to go with; I initially went with a manual SZ-R (step up from a A4 1.8t). For a non-turbo engine it’s pretty damn fast if you’re not familiar with big power cars, however I really did miss the pull of a turbo.
As a result I soon got TT urges and after a long time of looking I found a nice 6 speed in great condition so thought what the hell!.
For me the difference between the two is astounding when I first went on a test drive it really made the non turbo feel slow in comparison. I’ve never driven a supra with the auto box but always dismissed them due to personal preference, for me a Manual is the only option, an auto would just be a disappointment IMO.
If you have concerns over which model to go for id recommend the turbo, a non-turbo might make you happy in the short term but if your anything like me you will always want a bit more. Selling my non-turbo was a hassle; luckily I sold mine just as the markets started dropping so didn’t lose too much money.
Hope this helps,
Chris