Call a local kitchen cabinet shop. It won't be the cheapest, but you get what you want.

I just bought a 36" from costco online. http://reviews.costco.com/2070/11484453/valore-valore-915-36-inch-bath-vanity-reviews/reviews.htm

Their selection is limited, but they sell quality stuff. I have been happy with other furniture they sell too. Not as cheap as the big box stores, but also much higher quality with real wood.

We bought two from modernbathvanity.com - same style - just different sizes. They had a lot of choices. I'm pleased with them and the quality.

Get a quote from a local cabinet maker. I have found that they are competitive pricewise with the ready made ones, and as Jackfre says (above) you will get exactly what you want.

-Babka

I would try a local cabinet maker, I had ours made with upgraded drawers for significantly cheaper than one from the box stores. If you're flexible time wise, they usually love that stuff for good filler projects!

I came across this website the other day: www.luxurybathvanity.com. Ebay also have some nice vanities.

Here is a link that might be useful: Luxurybathvanity.com