This is the great thing about kit building, MODIFYING!   Get the SIG kit, and modify the wing section to your liking.  Get a carbon fiber tube, or aluminum as the main spar, and build a center section to mount the outboard panels to.  The hardest part in all this is securing the panels to the center section while maintaining scale appearance. You may be able to secure the tubes to the panels and from inside the cockpit secure them to the center.