A company or contractors who install radiant floor heating might be able to help you. The idea i have is this : An electric heater that hugs the underside of the granite. Granite though is a dense rock. How thick is it. For a bench i'm thinking at least 1.5 to 2 inches. It might take a while to heat up though.

Kiwi fruit (aka Chinese Gooseberry)

I think what you have done is amazing - so fresh and so modern - it is a great example to people like myself who have an old kitchen with good bones but no longer modern. So many people spend far too much money ripping out usable kitchens, that function well but they think they need to get the new and latest, often just to keep up with the "Jones". You have done an amazing job without the huge cost of replacing all your cabinetry. WELL DONE.

You are so right white is never out of fashion. I would set your budget and then look at your options. If you plan to stay in the house for many years then spend to the top of your budget (if that is going to give you a life time of pleasure), if you plan on being at the home for only a short time / few years then I would go mid range so it looks lovely, will have good resale value but you can invest your well earned money to go towards something else as well. Obviously Marble / Granite is the top of the range but there are so many cheaper and very attractive options these days that look just as good.