if you strap at 2 ohms i would run about a 5 cube sealed side, if you run more power then a smaller sealed side is needed to keep the sub more under control.
heres another one with a depth of 16 and height of 30 this one has the right sub displacement this time
im on my laptop and the screen is not tall enough to show the whole thing!
Before you buy the sub make sure to contact fi about the mounting depth, i recently bought a fi ssd 12 and my sub is closer to 7 inches when it states its 6.5 inches on the website!