i put on a corbin seat nice comfortable never slide around

If youre tall enough to be able to tolerate the seat being higher, you can raise the front of the seat. Several have done that & have had good results. Lots easier that gutting the seat AND, if it doesnt solve your problem, you can always go into the seat.. Cost, hassle, reversible, plenty of things to consider.

I didnt shave it down, but I "lowered" my seat by using some carpet padding/foam and some arts and crafts foam from walmart. Then recovered it using vinyl I ordered online. I used the stock pan and just trial and error fit layers and cut pieces how I wanted them.



I recently chopped the passenger section of the stock foam off and blended it into my "custom" front section so my wife would have a better seat since I went to struts, and then recovered it using the stock seat cover due to it being water proof and my vinyl not.

Heres my current seat setup. Ignore the rusted struts. They are painted and look better now  

I just bought some foam squares from Tractor Supply that is the heavy black memory gel type foam.  They are made to be squares of foam to kneel on in the garden.....and they are $ 9.99 each.  My wife slides around on the stock seat and when we set this on the seat she no longer slides.  It would be good foam to use for a seat bottom.