Hi,
This is the best SSD mount I've come across - http://www.akasa.co.uk/search.php?seed=AK-MX010
In the past I've used the single SSD mounts (like the type you sometimes get supplied with a new SSD) or just let SSDs sit free at the bottom of my case.
I thought I'd try and be tidier with my latest build so got a few of the Akasa mounts. I'm very pleased, though it would be better if the SSDs were further apart as it's a bit tight to get the power and SATA cables attached when the two SSD's slots are so close together - certainly the right angle SATA connectors are no good.
Regds, JR