Apparently Elbox have thought about this problem :-). I wrote to them and got this answer:
"Hello,
If you need to install the BVision or Indivision uder FastATA 1200 we
recommed
to rise the main FastATA board using the precision sockets.
Four of them are available in the BVisionKIT:
http://eu-shop.elbox.com/en_US/p/BVision-KIT/29If the FastATA is rised as high that it is necessary to rise the
Mediator board you can do it using the Mediator 1200 Riser KIT.
It rises Mediator 11,5 mm:
http://eu-shop.elbox.com/en_US/p/Mediator-1200-Riser-KIT/57Best regards,
ELBOX COMPUTER, Support Dept."
So apparently the solution is to rise the FastATA over the Indivision via the BVisionKIT and then rise the Mediator via the Mediator 1200 Riser kit.
Has anybody done this with succes?