36" is a very tight minimum & not often used any more, 44-48" is better for walkways & multi cook kitchens.

We have been a supplier of OSMO Hardwax Oils for a while now and have found that they have been great in all applications. They have an Oil specifically designed for Kitchen benchtops. OSMO Top Oil which is foodsafe and contains linseed, carnauba wax, candelilla wax, sunflower oil, soybean oil & thistle oil. You can buy it from VCS Products in Perth or Natural Timber Oils in Melbourne.

Ours is 950 and 2.4m long.I think as far as looks go, it depends how long the island is. If it's a very long island and less than 900, it would look out of proportion. Likewise, if it's a very short one, it would look wrong to have the width any more than 1m wide.

I actually think a mid-silvery paint would work well for the walls , and fit your brief , better than any off-white . Tied in with the charcoal and wood , it will look industrial , and you can add almost any tone of accessories and kitchen fittings , from blacks and wrought iron , to brass , copper , rose gold , and/or reds ,oranges , blues , yellows , most greens , etc .