Will this DeWalt #8 screw countersink bit be good for 1/16" aluminum?
Generally speaking you can use the same tools you'd use for wood to work with aluminum. I've done a number of projects using aluminum bar and angle stock with my woodworking tools, including a miter saw. 

However, since the metal is much harder, you'd probably have an easier time doing the drilling and countersinking separately. I'd drill with a standard high-speed bit, and use a countersink like the Ryobi you linked to finish.

On a related note, you'll not have much room for error when countersinking 1/16" stock. You might be better off with pan-head screws.