Gempler's offers two different valve adapters; I ordered both of them just to have them on hand. The one I used to fill my tires, however, was the brass quick-fill adapter. You can see them both here:
Installing Liquid Ballast in Tires | Gempler's
I used undiluted RV antifreeze (no water). Got it on sale at Tractor Supply for $2 a gallon. Used 25 gallons per tire (which is the recommended amount for my AG tires). If you have industrial tires, your volume might be different. This page has volumes for both AG and Turf tire sizes; you may need to search for Industrial tire volumes. Tires should be filled with ballast to about 75% of their volume:
Liquid Tire Ballast
I have the 4-speed, 3-range, shuttle-shift transmission. I have no complaints about my 3033's seat, but your butt may be different. I have about 50 hours on my machine.