Thank you very much Nick, that was helpful!
I would place the subwoofer in the rear corner that is in between the two couches.
If budget is really tight, go for the VTF-2 Mk3. You can always add a second one at some point in the future, and/or run it in maximum output mode (both ports open) for highest output capability. Otherwise, a VTF-3 Mk3 would be great too.
Hope this helps!
Pete - Hsu Research