We have been useing http://www.proboxhawaii.com/
system for the last 5 years and like the system alot. You can fine tune the board to your likeings, the fins can move 1/2" forward or back to make the pack closer or apart. You can change the cant in the fine by changeing the insert from 0 to 8 degrees. And also FCS fines will fit in the boxes also if you like.
here is were we buy our supplies http://greenlightsurfsupply.com/finsandaccessories.aspx
feel free to email me if you have any questions about them..