I recommend taking a sample of your cabinet finish to the store and hold it against the white and biscuit to see which looks better. And certainly, you can have the SS sink in your island, no problem.

Farm sinks are beautiful. Make sure your bottom cabinet will hold the size you purchase and that your cabinet maker knows you are planning a farm sink. ( he needs to make cabinet adjustments )

I agree to take a sample of the cabinet finish with you when you shop. Be cautious when you select biscuit in fireclay it can have a pink cast to it.

I love Rohl Fireclay sinks. The quality is amazing and the look and feel authentic. They are called affectionately in our showroom , the baby Bath. Rohl also has a new curved farm sink that is unlike any other.

oh course you can have a SS prep sink! You could also look at white Silgranite sinks by Blanco for something different.

Good luck ! sounds like a lovely kitchen going in! Exciting for you and your family!