I've used Choice Stationery for many years and find they are generally good.
However, I've just bought a new printer and they seem to be having trouble getting supplies for it. My first order was delayed about a week for black ink to arrive and my second order has been on hold for 2 weeks so far for coloured ink to arrive. A check today reveals there have no idea when it will arrive!
I hope this doesn't continue, or I'll have to look elsewhere.