hi there,

if its directly post workout it may not be a bad idea - a high glycemic fruit juice eg. grape juice with the whey. otherwise i remember a great postworkout drink posted here a hwile ago consisting of whey protein, dextrose tablet and some maltodextrin - or something like that, perfect post workout.

water is the healthiest option. milk will give extra calories (and most people cutting will cut out dairy) and remember that milk (well, anything really besides water) slows down absorption of protein, and the whole point of whey is its immediate absorption and rapid digestion (quick acting protein)