I also go to fabricators and pick up the double sink cut-outs. They take
a router and cut out where the sink will go, and they don't have any use for
the parts they cut out (but they're expensive, so they don't throw them
away) so I trade them a case of beer for whatever the suspension on my
truck will handle. They even help carry it out.
I've been getting EOS though, the corian is often thin and the EOS tends
to be 5/4.. more than large enough for pens. The cut-outs are about
20"x30" or so and weigh about 50-60 lbs.
Not much choice on colors, though. You get what they've got..