http://silverstonetek.com/product.php?pid=245&area=en
It is dirt cheap today, just €13 with included delivery costs.
You don't need the caddy, you could take off the print plate and just connect a bunch of things.
Apparently it is just a dynamic cache that is going to use the entirety of your SDD to cache the attached (looped) HDD -- supposedly the OS would see only the combined disk. Which means it would really see the attached HDD, but reads and writes are now cached between the SDD and HDD, with a hardware solution, only for one disk, but still. If you were to take off the print plate and put it into its own nice packaging and all you need is a few cables to connect the stuff, you could hang it into an ordinary case without the caddy space with the print plate connecting the motherboard, HDD and SSD together. The cheapest and easiest way to hang an SSD "in between" a HDD and the motherboard, in a hardware way.
