I have two brand new swivel wakeboard racks (though they might be usable for surf racks as well depending on the size of the board -- ~ 1 1/8" distance between forks) that I picked up at the end of last season to replace my standard racks but I have since found some swivel racks that I prefer instead. They are a set -- one port and one starboard -- though it looks like they can be easily interchanged depending if you want the clamp handle on the bottom or top. It looks like it will work on a 2" to 2 1/2" tower diameter and possibly even smaller than that with rubber spacers. They should be compatiable with both the old style rad-a-cage as well as the Oz towers.

I got a good deal on them -- only $200 each -- and will let them go for the same amount plus shipping. Includes the two racks and all mounting hardware.

Take a look at the pics and let me know if you need any additional dimensions.