I do not really have any ideas for you, outside of hiring someone to make these things for you.
I may soon raise my three fronts so that the drivers can clear all of the wood framing for when I get an AT (acoustically transparent) screen wall.
However, in your case, I would experiment before raising the speakers height, if only to make sure you don't really need the funky look. Some speakers will have dramatic differences in freq response at your ears, depending on the final height (and with lack of angle to be onaxis). Maybe a couple of thick phone books under each, temporarily, to see if you even care, or if there is even a difference that you can perceive.
For the center pedestal, I would encourage you to consider stuffing it with insulation that can absorb sound energy well just in case that this little box/pedestal happens to very resonant. I would even consider having the pedestal high enough to put some Auralex Mopads and/or speaker dudes under the speaker, etc. Good luck!
BTW, please let me know what you do come up with for raising mains, if you do go that route. I haven't figured out what I will do if I'm nuts enough to continue with my plan.