It would be helpful if I had a drawing, but I don't so I'll try to be concise.There will be a large rectangular island containing an under-mounted prep sink. Standing at the prepsink you are looking out towards the dining/great room. Island countertop will be butcherblock which will be oiled so that I can cut directly on it. Behind the prep sink, along the wall, is the range, flanked on either side by the all refrigerator/ freezer. To the left of the prep sink is the perimeter counter with double stacked ovens, counter space, main sink, more counter run. On the opposite perimeter (to the right of the prep sink) is a beverage/ snack center with a small counter top and bar sink. Perimeter counters will be Calcutta gold.

I was leaning toward an undermounted SS prep sink and smaller bar sink, but I'm not sure. I've recently fallen in love with several waterstone faucets and the Tuscan bronze finish is really calling me. Not sure how the bronze finish will look with a SS sink. I need to see the faucets in person, but the antique pewter might be an option as well.

There won't be a lot of other stainless as I plan to have the fridge and freezer fully integrated. The range will be a bluestar, which might be stainless or maybe a color (dark olive green?). The hood will be covered. The dishwashers will be paneled as well. The double wall ovens will be stainless. Cabinets will be a grayish-green or a mousy sort of brown and there won't be any uppers other than the beverage center and the cabinet containing the double wall ovens.

We are bulding on a wooded lot in the pacific northwest. Going for a modern sort of cabin/ farmhouse look with cottage/craftsman/rustic touches.

So I guess my question is how will stainless undermounted prep sink and bar sink look in the same kitchen with a large white fireclay apron sink? Also, how will the tuscan bronze finish look with the SS sinks?

Here are some photos of the faucets I'm looking at in the Tuscan bronze finish.
For the main farmhouse sink:

For the prep sink (this may be too large, also shown in the antique pewter as opposed to the Tuscan bronze)

Bar sink

Have you ruled out a Blanco silgranit? The cafe brown would probably go with both your wood counter and your bronze faucet.

I have a black walnut island counter with undermount prep sink. On the Carrara perimeter I used a metallic gray cleanup sink as that color looked best with the marble. I seriously considered using the cafe brown prep sink in the island to match the wood, but I had issues with the sinks not matching (minor issue) and with the stainless faucet looking strange with a brown sink. I ended up using the metallic gray sink in the island to match the perimeter.

Or, what about a copper prep sink?

I haven't ruled out silgranite, but if I go that route then what color for the bar sink (white-ish to match the Calcutta gold marble?) if I did that then I'd have three different sinks going on.

Also, how do the silgranite sinks feel? Are they like corian? I'm worried that they might look like plastic sinks. I feel like I'm going out of my way (and over budget) to stick with natural materials, so maybe I want a sink that continues with that. I don't mean that everything needs to be green or truly natural, just not plastic, vinyl or other obvious composite materials. Hope that makes sense.

Oh and off topic, you used a custom cabinet guy out of Buckley, right? Im pretty sure I'm thinking of your gorgeous white shaker cabs and walnut island. How did you find him price-wise? I keep reading these stories where people find custom cabinets to be the same or less than the semi custom, but maybe they are all lucky enough to have Amish communities nearby.

My cabinets were made by Cornerstone Cabinetry, a one-man shop in Buckley. His quote equaled or was better price wise and included much more than quotes I received elsewhere for semi-custom cabinets. My cabs were made without fillers and included end panels without extra charge. I received personal attention, hand holding, and patience with last minute changes as the cabs were being made that I doubt you'd receive from a big box store or many other places. After experiencing a custom shop and products, I can't believe I would have been happy with anything else.