Interesting that I should stumble upon this thread. I was trying to come up with a similar concept - a gravity-based system with the kettles at eye-level. I prefer the appearance of the single tier vs the triple tier systems. I don't like the idea of having a kettle of scalding water sitting atop a high rig.
I was googling around for scissor jacks that could be adapted for this. All I could find were ones strong enough to lift cars. I've also considered trying to design some kind of vertical trolley lift to which would be attached the square tables for the kettles. I can't find anything. I'd like to adapt the sort of mechanism used by some of the Genie Lift devices such as:
I guess I don't have the energy to try to design an adaptation of this scaled down to the loads I would use in brewing.
I would be interested in hearing more about your build - including pictures. There's a Harbor Freight store a couple miles from me.
One concern I have about these hydraulic tables: it appears that you pump the foot pedal in order to raise the table - hence the large kettle full of hot water or wort. I'm wondering if the jerking of the upward movement would cause a lot of sloshing around inside the kettle enough to make the kettle unstable.
Please keep us posted.