For my current build I decided to take a chance on something I'd barely heard of and knew even less about.
The 8" Motus UH205PW1.
These T/S were taken before any break in so Qm will come up a bit.
Vas: 56L (a bit smaller than spec)
Dcr: 5.01 ohm
In a 1.6CF box with a 3" dia, 10" long port and .7ohm DCR on the coils this will yield an F3 in the Mid 20's and take about 50W of input before reaching Xmax above Fb (~28hz).