Not all "fun" cars can be had with a manual trans.
You won't find a second or third gen T-bird so equipped.
If you do, It will be a three-on-the-tree (BTW, I frown on people who can't handle one of these).
But by the time you go 3-on-tree, you might as well have a C6 automatic.
Especially, if it has been reprogrammed with an OD.
If I were to go "modern", I'd like a '66 Mustang Notchback. With any of the available motors, including the 200Cid straight-six, with a three or 4 speed manual behind it.
Again, disc brakes, and "decent" seats would be a must.