Personally I would not purchase from either of those 2 shops. Even with their discount codes its still expensive.
Try https://www.autodoc.co.uk. They based in German and does take about 2 weeks to arrive.
Its free delivery if you spend over £150.
I purchased 4 shocks for my 2009 A5. OEM Sach brand £40 each rear and £52 each front. Lemforder front strut mounts £9 each side. You download their app on your phone and keep an eye on the discount. It changes daily..
I try not to go lower than OEM quality. Sach is normally OEM for Audi and BMW.
I am sure nothing wrong with KYB.
I am curious how much garage charge to replace front strut on A5. I am looking to replace these myself when weather improves. Did the job on previous vehicle BMW and took best part of Sun morning to complete both sides.