I purchased a lot of genuine Mahogany (as opposed to another wood like santos dyes mahogany) from Rare Earth. They also sells several species of reclaimed lake wood. I'd buy again from them, although at the depth, 3/8" for glue down, I ordered quite a few of the longer boards were warped.
Rare Earth is a 20 year old manufacturing and importing company that sells many rare and beautiful woods for flooring, decking, inlays or just lumber for table tops or baby's blocks.
The quality of their wood as well as their pricing will be better than anything you can find in New York (price list is not on web yet, but they will fax it), and they easily ship to customers all over the country. For a more beautiful and sustainable solution, this is another great resource. (Thanks, Jonathan!) MGR