I know i wont be able to afford the exoctica3, but i would give my IMO,
How about switching the tweeter and mid, so that the tweeter would be at the bottom, this way, the tower can be made a little higher. The gold one at axpona give me an impression of shortness specially when the bottom side are wider. To me, towers that stand tall are very nice looking. As far as stiffening the cabinets with simplify cabinet works, how about some birch ply. I think they are a little more expensive then mdf, but could be jutified in the exoctica.