specialized sink sizes

I am trying to find a stainless steel sink, less that 3" deep, less than or equal to 12 inches square otherwise. SEcondly could be a plastic sink I suppose. I'm trying to make one that flips up into the wall compartment for the Elf Cottage and it must fold up between the studs with a maximum thickness of 4 inches, including the drain elbow.
The faucets I am going to have a garden hose type valved "Y" but instead of separating one flow into two, it will join the hot and cold and be flexible enough to go back into the wall when I fold up the sink and come out over the sink when I fold down the sink. (just enough to wash hands and for running water to fill drinks, maybe a sponge bath inside the trailer... Otherwise, I'd just water proof all the walls, and the cabinet doors, put everything away and have shower heads at the ceiling peak to shower indoors... put a drain in one corner with the right tilt when I park...
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The faucets I am going to have a garden hose type valved "Y" but instead of separating one flow into two, it will join the hot and cold and be flexible enough to go back into the wall when I fold up the sink and come out over the sink when I fold down the sink. (just enough to wash hands and for running water to fill drinks, maybe a sponge bath inside the trailer... Otherwise, I'd just water proof all the walls, and the cabinet doors, put everything away and have shower heads at the ceiling peak to shower indoors... put a drain in one corner with the right tilt when I park...
