8 and 10 percent crosslink have similar capacities and use the same flow control as long as they are standard resin types.
The actual unit capacity is much less than claimed. It should be set up according to industry standards. 20,000 grains per cu. ft. if the system is regenerated with 6 pounds of salt per cu. ft. or 30,000 grains capacity when regenerated with 9 pounds total for your system.
The company who is installing it should take care of this part for you.
Clack valve based systems must be installed by the company selling it. I assume they are installing it, programming it etc. for you...