However, a site transformer, SD TR750/1 would as well, is isolated and
it doesn't matter if it gets a bit wet in the kitchen.

That's the one I was looking at. If buying one, I'd be tempted to buy a 3kVA
tucked away in a spare cupboard. You could then run a couple of 110V US
style sockets around the house to a 110V industrial plug. Your US visitors
will love you, and you can always borrow the transformer every time you hire
something 110V from the hire shop and want to save yourself a couple of
quid. Alternatively you can start buying proper 110V tools yourself.

Christian.