Dennis, I use the On Stage model KS7150 for my Nord C1. Best $49.00 single-keyboard stand made, especially for anyone using lots of foot pedals or an organ pedalboard (it's about the only one that fits my PK7a and is also high enough for a 6'5" organ player like me to comfortably fit under it. I have the KS7500 second tier but in my opinion, it sucks. It seems (to me) that no amount of adjustment will make it perfectly level and balanced. YMMV. The best stand (that I have, and I have 6 or7) for second tier setback is a heavy duty Quik-Lok (don't have the model # handy). I have my PA1x Pro on the bottom and my VP550 on the top - no problem seeing and getting to everything on the Korg with only about six inches of elevation.

I hesitate to recommend anything because it depends so much on the layout of the bottom keyboard and how comfortable you are with the height of the top keyboard.

chas