I generally advise against using an undermount sink. One reason for this is that, over time, an unsightly mould ring can develop on the silicone between the sink and the stone.
In addition, in the standard fitting of an undermount sink, the stone edge is vulnerable to damage when pots and dishes are placed in the sink. This can be minimised by a design which sets the stone further back from the edge of the sink.
Or … my favourite solution … mount the undermount sink on top! (Most undermount sinks are designed to fit either on top of or under the stone). The result is a slimline, clean-cut finish without the disadvantages listed above.
For more friendly, honest advice and a quick, free quote, give me call anytime for a chat.