Final (?) update
I got tired of waiting for Emotiva and even more tired of trying to 'fit a square peg in a round hole' so decided to 'reshape the hole'.
I 'flipped' my placement around and decided to put the subwoofers against the back wall. This freed me of my depth limitations and I am the proud new owner of a pair of PB3000s. That should be enough bass for now!
Now my last decision is, should I place the THX-365ts mini-towers on new stands up front or move them to the rear and buy a pair of THX-465t towers?