Q's about dual bay hot-swapable drive enclosures

[Pancake]

Hi.

I am looking into buying the following enclosure or something similar

http://www.cooldrives.com/bliceul2fi80.html

It is a bit more advanced than what I'm used to and I don't understand the option between getting it master/slave or master/master.

I want to be able to dedicate individual drives to different FCP projects and swap accordingly.

Any help would be greatly appreciated.

-Pancake