Honestly, you never once mentioned how many speakers or channels you were looking to use, so I felt it was an honest question. I'm highlighting some statements from your first post that made me think you wanted tons and tons of speakers. There was never any mention that I saw of a speaker handling multiple pipes, so sorry if I didn't understand that.
Knowing further what you want I think you might actually be well served by a complete HSU speaker and sub system here. One of the systems here: Maybe the 5.1 and pick up a second sub
http://www.hsuresearch.com/products/hybrid15-CCBpkg.html
My thinking behind this goes as follows:
The VTF 15h MK2 is a good performer down to 16 Hz. Two of them will help to even out room nulls and modes, giving more even bass throughout the whole listening space.
The CCB-8 because it's a coaxial speaker and is modestly priced, it also has great dispersion and due to their size will be easy for you to place them throughout the room.