Bother. The Apple Store was out of blue 5th gen cellular iPad Air 5s with 256 GB storage. The only colour available in that capacity was Starlight, which is an off-white with a hint of cream. Anyway, I bought it and an Apple Pencil 2.
Suitable keyboard cases with trackpads can’t be had at present but I should be able to get one from an office supplies store, I have ordered a Logitech Combo Touch case/keyboard/trackpad.