I would put black glass behind the hob if not a shade that matches the units. Not being a fan of splashes of colour I would have the accessories in chrome then add something interesting like a beautiful wooden fruit bowl or a white bowl.

I think since you have gone light with all other items, black would be nice. You can then add splashes colour in the accessories. (Kettle, toaster, coffee/ tea jars, etc). Yes, I have also just come from a glass showroom now and asked about antique glass behind a hob and they said no way as it would be at risk of cracking.

If you want to match the accessories to the splashback, look at accessories first as you may be limited in the colour choices of, say, kettles and toasters. You can then match your splashback to the chosen colour. Coloured glass is the neatest option for splashbacks and can be customised to any colour- I would advise running it along the whole wall, not just behind the hob, without wooden splashbacks. You need a colour that tones with your wood worktop without being too harsh - a duck egg blue would work, or a soft sage green. I agree that chrome accessories would be another nice solution....

I would stick to stainless steel for the hob back splash having read your wishes and as you wish for wooden up stands elsewhere. Above the wooden up stands I would make sure the paint is washable.

When the wooden up stands are installed make sure there is enough room for your cable flex and plug to go into the sockets. You might want to change the white sockets, for stainless steel or something that matches whatever your choice is for the backsplash.