My grand daughter is disabled, with a rare thing (WHS) and has no immune system. We manage perfectly well shopping on line and I honestly think that parents are responsible for subjecting their kids to miserable experiences causing them and others distress.
You do not need a 'team of helpers' you just have to get on with sorting out, what it is your own child can tolerate by way of external stimulations and if that child can't cope, then shop on line and spare everyone the hassle.
My daughter has 2 other children to cope with and is studying p/t, she takes appropriate steps to ensure the comfort and safety of her child, by putting her first and not tking her to places where she can't cope.
I step in and have the children if she wants to go and do 'trying things on', but when I see all the poor kids dragged around supermarkets, while they go into frenzy or melt down and their parent wanders about (on the phone more likely than not) taking no responsibility for the havoc caused, I could weep.
There really is nothing you can buy, that is more important than the comfort and well being of your child and the internet has made everything else so simple. Shops are open all hours now and 7 days a week, children susceptible to sensory overload need not be taken there, it cant be good for them.