are you actually selling jon's work or do you have plr on this script? we used 10x10 many years back and if you have permission to rip the code would be interesting to know...
good choice... you would not want to get flamed before you got started here!
jon's work is old now, in internet terms, but is still IP to him... if you are really interested you can ASK to develop / recore the script into something updated maybe...