One of the things that you learn when rebuilding a house, as we are, is that you don't know very much about anything. For example, just what is an undermount sink? I had to go and ask but to aid you, here's the answer. It's means that the sink is mounted under the counter rather than dropped in, so it'll be flush with the surface.

Having found that out of course I went looking for some and if you click through that link you'll find what I did. Firstly, stainless teel undermount sinks which are vastly cheaper than normal. $100 or so for a generic one rather than the more usual $400 for a brand.

And secondly, something which I think is rather cool. Their granite undermount sinks are covered with silver ions: that means that they're bactericidal, killing 99% of germs upon contact.
That is pretty cool, isn't it?