They both have AC4/class32 abrasion resistance. QS is 7mm, B&Q 8mm but QS has 20 year "warranty", B&Q 15 year (FWIW). Personally I would use QS, if for nothing else for continuity in case you need some more - B&Q will not necessarily maintain the same supplier year on year. In any case, the underlay has a huge amount to how laminates feel. If you put a thinner laminate on a squashy underlay on a floor with even the slightest unevenness, it will feel bouncy. My preferred underlay having tried a few is
https://www.quick-step.co.uk/en-gb/accessories/qsudltl9_thermolevel, but it isn't cheap. However, certainly with 8mm laminate it gives a nice solid feel underfoot. My 2p as a non-pro but experienced DIYer with a good few floors done over the years.