Gareth. Is it a thing that you cabinet makers are starting to look at, the prospect of getting more than 8 PCI-slots on the cabinet?
I have had buildings earlier where the standard 7 slots where not enough...
Back then I settled on the Stacker STC-01, since i then could use the lover PSU-bay for the purpose, with a home-made bracket.
IMO it have been a huge problem for years, that you only got the 7, max 8 slots, since some MB makers don't always take this in to mind, when making tri/quad 16x slots on there motherboards.
If/when you populate all of these slots, then you cannot use those USB/Firewire/eSATA brackets, since no more free slots.