Quite a lot of options really, a fair few low carb options out there, personally I use myprotein diet whey simply because its good value, it does have a few carbs but I tend to use only half a serving post workout when a few carbs are not necessarily a bad thing, and it does not spike me, I add a bit of fruit , Greek yogurt, peanut butter and almond/soy milk etc.......
http://www.myprotein.com/home.dept
But as said their are lots of zero/low carbs protein shakes out there at different price ranges maxi do a low one at home bargains/B and M.
Another I have tried recently is making my own whey, I have been making my own Kefir for a while.......basically leaving Kefir grains in milk for 24 hours which converts the sugar and makes a fermented probiotic drink, very easy to do, but if you leave it for longer it turns into Curds and whey, the curds make a nice soft cheese which leave you the whey to use as you wish...
Or you could go old school and GOMAD (Gallon of Milk a Day)
but use almond/soy/hemp milk instead...
PS. IMO Avoid Holland and Barrett, Overpriced and the quality can be questionable , far better options online with Amazon probably the easiest for most people and they often have great deals .
This may be of interest , I actually stopped using supplements for a year or so after watching this, but they are useful convenience wise ....