Buy the TransGo HD-2 kit for the 4L80E.
Cryo'd parts is a good idea
The year of tranny you have is good.
The Sonnax reverse boost valve is a good addition.
Good quality Alto red fricrions work well with standard steel plates. I am not a fan of kolene steels.
A quality rebuild with the proper clearances and fresh bushings the tranny should work great.
Some people are like Slinkies... Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs.