Single order with each of the several suppliers I contacted. I ordered 5 from www.poshflooring.co.uk but others were only 2 or 3 depending on their policy (some limit to 2 or 3 at a time), or whether they had what I wanted.
For anyone wanting oak there is an abundant supply but have lots from previous flooring jobs.
Definitely worth calling in person to any local flooring companies I would have thought as they may well also have old discontinued samples or even odd lengths of board very cheap or even free. I'm going to do exactly that when I have time.