Hello jessemilyrabbit, I noticed your question regarding your need for brass tapware. We actually build tapware in Victoria and can offer these kinds of finishes: antique brass, tumbled brass, raw brass, raw polished brass (which will naturally dull and age) and gloss or matte black. Faucet Strommen Aged Brass Faucet Strommen Antique Brass Light

It would not be unusual to have black knobs, handles etc and different hinges. It is personal preference though.

An undermount stainless steel sink will match well with your brushed gold tap and white benchtop. Although different in colour, the sink and tap shared same kind of texture so It won't be distracting. Colour wise, the sink will match perfectly with your white benchtop. We got some photos of our customers who have used the same kind of design before, check out the link below if you would like to have a look. https://fontaineind.com.au/colette-kitchen-laundry-tap-mixer-brushed-gold https://fontaineind.com.au/ariella-kitchenlaundry-mixer-tap-brushed-gold

I have a top Mount double bowl sink in my kitchen with stone bench tops. I don’t think it looks cheap.... AND, the second unused hole is not just “filled” by the plumber, but a “faucet hole cover” is installed and will sit almost flush with the sink surround. If you have under mount sink in your kitchen, how are you going to have dishes draining, before immediately hand drying. You will have to put some kind of draining board on the STONE, and that will look cheap. But if under mount sinks are included in the build, then go with that. But they don’t include somewhere to place pots and pans after washing and before drying by hand. Because you have stated that you are only having a single bowl sink in the kitchen.