Hi Julie

I use stainless steel sinks on the majority of my projects but have used composite sinks many times too. You have more configuration options with SS, but it will scratch. A chrome grid in the bottom of the sink is a great way to minimize that. The composite sinks are more durable than SS, but the colors are limited. I'd suggest taking a good sized sample of your countertop stone to the plumbing showroom to see if the color is right. If you can get a sample of the composite that will help as an alternative, but some brands (like Blanco) have paper samples which do not seem very accurate.

I'd also shy away from using black composite, as it can show (hard) water spots more than SS. I've had two clients say that they regretted choosing black on their prior projects.

~Steve