Wickes' Click & Collect allows you to check stock at local branches.
IME almost everything I look at in B&Q has a terrible rating - obviously you can't be sure whether reviews are real but being able to search reviews for particular terms (eg I've been doing a lot of looking a different adhesives recently, trying to find one that I can use to safely repair a broken milk jug as well as for the larger job that's prompting the purpose) has been really useful to me. Plus some of the photos in Wickes reviews have been useful.
Anyway, good luck with your project/s.