UK Modellers...what cardstock and where?

This question is for UK modellers only...

can you please recommend a type/brand of cardstock
and where to purchase it. (Name of a store or outelt?)

I have a customer from the UK who is new to paper modelling
and has asked me what paper/card to use and purchase.
I've given him as much info as I can, but he claims not to be able
to find or buy anything like what I am recommending, in any store.
I have tried to recommend certain stores but he has had no luck.

To be honest, I don't think he is asking for the right thing.
Or maybe hes just dealing with staff that don't understand what he is looking for.

Its difficult to point him to the correct thing when I am working from the other side of the Atlantic!

What type, weight, brand of cardstock do you use?
and most importantly, where do you buy it?
Can you also tell us what you pay?

...
FYI

I use 65lb plain smooth white Cardstock...176gsm...for most of my modelling projects.
I also use 110lb (199gsm) for parts that require a little bit more rigidity.

Most of the time I buy Staples (an Office Supply store) brand 65lb cardstock.
A 250 pack costs me about $17CAD

I have also used Coverstock (67lb) but I find it slightly thinner, and a bit more expensive.
Its also a slightly smoother finish, so it prints nice.

My 110lb cardstock is Wausau (Exact Index) and cost about $20CAD for the same 250 pack.