Just wanted to reassure you System, that going for the 90's is the right choice. I'm only an amateur at gymnastics, yet after 6 goes on my 90kg ProJumps I'm already bottoming out (I weigh 65kg). So with your background you'll definitely want heavy springs! Personally I hate the knee bar. So I just moded my Pro-Jumps.
There is a thread on here for how to make them, however, a search for 'Cuffies' didn't bring anything up, can anyone enlighten us?