I want to turn this old buffet into a two sink, bathroom vanity.

You will loose the drawers unless you build up the top to accommodate the plumbing, If you don't want to keep the drawers, just remove the fronts and secure them to the buffet; then cut out he top for the sink and make one or more holes in the back for the piping.

No problem. I don't know what your style is, but I would paint it with Annie Sloane in a color that matches in with your tiles eg. grey, white, etc. Than it is just for the plumber to cut in the holes for the basin and connect the plumbing. It will look great.

HGTV has a good tutorial: http://www.hgtv.com/design/make-and-celebrate/handmade/turn-a-vintage-dresser-into-a-bathroom-vanity

i love it, also would painto it to match bathroom can see it a two tone I'm sure will be lovely

They have some great videos on YouTube showing you how to. I think it would be stunning!

Try old english scratch cover, dark brown, but you need to water proof the top, buy sinks first and see how it looks, I used bowls and only made little holes to attach, depends how high the cabinet is

Are you SURE you want to use this? You will end up with NO storage. I would look for a buffet with more drawers. I used a dresser with ALL drawers for a sink cabinet. I just cut out the backs of the drawers and re-built them to accommodate the plumbing.