Clutch, transmission, and shifter research thread! Save money and frustration!

If you are richer than necessary, there is Hewland.
https://www.hewland.com/
This is a high-end European motorsports-targeted brand. I think they even market to the F1 teams, but they DEFINITELY sell to Formula 2, the Farm League of F1.

 

Shifter.
As I refer to the shifter on the Hellcat as the Rubbermaster 5000 Shift Suggestor, I did some digging and found the Ray Barton Engineering shifter is boasted on by anyone who has gotten one as reconnecting the driver back with his car.

I have been driving along in 3rd gear and carefully and intentionally tried to shift up to fourth. I was doing just that to make sure there was not yet another missed shift.
Instead, I was given SECOND. The tires chirped, the rear and bucked, OMG. Fortunately, no engine damage.
This was not due to being in a hurry or not paying attention. The stock shifter just suxx0red.

You can use the stock shifter knob if you wish if you don't like the look of the various custom levers or knobs from Ray Barton.

It has adjustable stops on it, also, and is fairly vigorously self-centering, so there is little doubt as to which gate you will be lined up with. If you add no pressure, you are in the 3-4 gate. If you add pressure left or right, you will be in 1-2 or 5-6. It leaves little doubt.
MY dream would be a Ferrari-style gate for the shifter, but I have heard the Barton cures people's shifter woes.