This is a quick sketch of the cabinet based sink stand that I built for my last darkroom. It is modular, with "sink cabinet" that rests on two base cabinets. On one side I had drying screens and on the other side a few dividers for storing trays. Shelves would certainly be another option. This can be as basic or a fancy as you want. It could be build out of AC plywood and painted. For mine I used shop grade maple plywood with maple edge banding for the base cabinets, AC plywood with Formica laminate for the sink cabinet. The lower cabinets received 3 good coats of polyurethane. The space between the lower cabinets was for the water supply, drain, and water filters.

None of this is hard to build and can be done with a Skilsaw if you are willing to clamp a straight edge to the plywood when making your cuts. If you have a table saw that's even better.

Roger