It seems the A85 is available only at Currys at the moment, so I suspect it may be exclusive to them. Guess that removes the A85 from my shortlist!
The A8 stand has the advantage of being able to convert so that a soundbar can be installed under the TV. Doesn't look like you can do that with the A85 stand.
This might be old news; the A85 variants are available from Currys and Sony Centres, having the straight out feet, this has the advantage the feet are 85.5cm apart versus ~100cm for the John Lewis A8.
For people going for the A8 the feet have two positions, the higher one can support a sound bar, see picture here
Review: Sony KD-55A8 (A8 series) OLED TV
Review: Sony KD-55A8 OLED TV supported with a powerful Android chipset, new menus, remote, and the X1 Ultimate processor and without no full HDMI 2.1.
allhomecinema.com