Personally I'd say that the mismatched wood under the tank is more of an eyesore than the filter or CO2 can, why do you have that?
The table doesn't look like a fine piece or antique so if you aren't willing to replace it with something more appropriate for your needs then perhaps you could modify it? Cut a large notch in the back of the middle shelf to accommodate your equipment which can hang off straps or even a lower shelf in the back could be fashioned. Also some sort of curtain, board, or black lacquer could be placed in front of the equipment to hide it.
I wouldn't settle for anything less than an Eheim 2215 for that tank - which would likely work just fine on its side if you had to.
I guess you missed the part of my initial post that said " (There is a mini-stand for the tank that might
go away, which would drop that by about 3.5")" The stand that's there is only temporary... I had planned to have a custom stand made from glossy materials, but haven't decided for sure on the final design. So the one that's there is a very temporary placeholder, that I threw together to get the tank to the right height for the final stand. I didn't spend much time on building it since it was only temporary. Even without a stand, the difference is only a few inches of host height, so that wouldn't change anything with regard to the height of the shelf.
My WIFE is not willing to replace the table... or let me cut into it. (Not many wives would, IMO) So I work with what I have.
The equipment is
hidden, from the front and right side, and by the bins to the left. The only equipment you can see, normally, is the canister on the floor. I removed the false box fronts that are usually hiding the self contents for the photos, just so people could visual the space (and headroom) better.
Canisters on their side aren't a good idea, in my book, for the reasons mott states in the post above.