Put in a vanity...you might be able to do a metal plate then have holes drilled and tapped. For attaching to the studs, you'd want the holes either countersunk so you could use large flathead wood screws, or counterbored so you could use lag bolts. If you got 1/2" thick plate, it would be the same thickness as the drywall, and if the sink was wide enough, you may hide it entirely. On the machine screws holding the sink up, I'd want to use some thread locking compound. This might be overkill, but should work.