I don't know why he thinks a drawer (1 front but really just 2 side compartments, maybe a small tray in front) would interfere. If it slides in after the sink is installed, it will slide out too to remove completely.

I just had the plumbers currently working on my bathroom tell me they did exactly that for someone. The person bought a vanity with a bottom drawer and didn't understand their pipes came out of the floor. They cut out the drawer to fit. Obviously it depends on the plumber.

...They tell a lot of stories. Plumbers like to talk! :)

Take a look at the 2 "washstand" threads - nice drawer modifications shown on both of those, and while the pix only show them partially pulled out, I'm sure they come out all the way. Your drawer may lose more space depending on your sink (big dropin sink might take most of the drawer) but the idea is the same.

Here are my photos of our vanity conversion. ajsmama, I added the drawer-free interior shots that you asked to see in the other thread.

The photos are from my phone, the lighting is terrible, and it's impossible to get back far enough to show much, but I hope they help.

Here is a link that might be useful: powder room vanity

I did this in my own master bathroom. I have a pedestal sink top set into the counter top. the bottom of the sink has a bit of a flare to it, so I made the drawer "U" shaped.

Where a normal drawer has four sides, this has eight. I still dovetailed all the joints, I didn't have a trouble with the drawer in terms of making it. Its on drawer slides, it's fully removable, there are no restrictions in terms of accessing the plumbing. There are no stability issues.

It's the top-center drawer in the first photo:

That's exactly what I was talking about when I said you may have 2 drawers and maybe a front tray with a single face. See, no big deal!