My local branch is in Leeds just opposite where I work (which is handy). They do a range of different flours starting at £6.99 for a 15kg sack (sometimes cheaper if they're on special) and other stuff like tinned tomato pizza toppings, bags of grated cheese, tinned chillis, frozen pepperoni, garlic sausage etc. They specialise in stuff for take aways and have a few branches over the North. Probably a cheats way of doing things but great for easy bulk buys if you're having a party. This link takes you to their site
When making pizza dough there are plenty other variables that need worrying about before you get to choosing a specific brand of flour. Fresh or dried yeast? or sourdough culture? How long to let it ferment? How much to knead it? How much salt to add? Oil or no oil? What level of hydration?
To be honest, as long as you use a good quality strong flour and it's reasonably fresh, any make will probably do.
Recently I have been using a strong Canadian wheat flour (Marriage's) that I bought in a 15kg sack from Costco, and it's turned out lovely each time. Before that I was using Allinson, Waitrose, even Tesco's own label strong flours and they all worked.