I would go with a protein shake, try it and see if it works out good for you. How much cash are you looking to spend? Someone else can probably recommend a good powder, I just buy the 'student sale'. Which is either $100 CAD for 10 pounds of either prolab or ultimate nutrition.
If you want a good tasting one, but more expensive go with Muscle Milk.
proteinfactory.com has a good prices if your buying online.
Thanks for your help, I've just ordered some muscle milk.
This thread is three months old, how are you doing so far?