Widespread is an 8 inch center.

Look at the Kohler sinks, drill down each model and look at the specifications to get measurements. I frequently wash my hands so I wanted a ledge to catch the water drips around the faucet handles. Also pay attention to matching up a sink that fits with your faucet spout length. Kohler and Toto sinks are good quality. You can find good prices online - even home depot online on the more popular models. Amer Std has quality control issues to where the sinks may not sit flush with the vanity top. and porcelain blemishes - same as their toilets.

Here is a link that might be useful: Kohler Drop in Sinks