I was in Walmart today and found something new. Weider Pure Pro Shake, ready to serve, not powder. 354ml can was about $2.80. 4g carbs, 35g protein, .5g fat 160 calories, so it looks like the numbers add up ok. It's sweetened with Sucralose (Splenda) and Ace-K, no aspartame and is made with whey protein, not soy. Here it is on their website: http://www.weider.ca/Pure_pro_shake.htm
They only had "creamy vanilla", but it looks like it comes in chocolate too. They also have online ordering in Canadian $, don't have this shake there but they do have some protein powders.

I haven't tried it yet, I'll let it get nice and cold and try it in the morning.