Fantastic bathroom features a gray washstand painted Farrow & Ball Elephant's Breath accented with nickel cup pulls topped with a rectangular vessel sink tucked under a vintage style wall-mount faucet lining a white beveled subway tile backsplash.
Pinned for the idea. Not sure how much I like the extension over the toilet. If were to do, vanity top should be one piece, with no cut line. Also: Consider how much the extra counter space would be needed.
Small white bathroom features an Ikea Yddingen Washstand donning Lewis Dolin Round Bar Pulls in Brushed Brass and a white porcelain sink paired with a brass faucet placed under an Ikea Skogsvag Mirror mounted on white subway backsplash tiles lit by a by Cedar & Moss Vista Sconce.
Rather than using standard cabinetry, consider creating a sink vanity out of an old dresser. A cabinetmaker can cut a hole in the top of the dresser to fit a drop-in sink. Cover the top of the dresser with a slab of countertop in the material of your choice. Paint the dresser a punchy color to update it even further