UK Post op diet options - Band

So the WLS company have sent me the pre and post op pack.
In it they advise to use Weigh to Go shakes/soups and products (This is their company's products of course they would recommend it).

Unfortunately they haven't offered much in the terms of other options for shakes/soups etc.
Their option works out quite expensive and from what I have seen is quite high in sugar...

Has anyone got any recommendations for other shakes or low cal gastric band friendly soups.
I am in the UK so that would be helpful.