Hey guys,
I was desperate to get the Blackmagic SSD cases and couldn't find them anywhere unless I wanted to buy a box of 90. Anyway I've found someone on eBay selling them
http://www.ebay.co.uk/itm/Blackmagic-Design-Cinema-Camera-SSD-Case-/181133962072?pt=UK_Photography_Movie_Camera_Accessories&hash=item2a2c6ceb58
It has a buy it now of £8:50 which is alright with free shipping. I made a best offer and got a couple for £8 each.