I used to have a 23" Lokar shifter in my truck. Installation isn't bad, but the trans will need to be removed. It can be done with it in, but things will much quicker and easier with it out.
Lokar makes a great product. I loved mine, and in many ways, I miss it. I removed it to go for a cleaner interior look, but now I want another one. I may go 16" this time, though.