I would clad it in horizontal wide timber flooring planks. Myself I'd go a grey, weathered timber like an oak, the engineered flooring can be bout in packs, so a single pack would create a feature inexpenssively. It will provide the oppotunity to introduce timber details in furnishings or kitchen accessories. Natural timber softens modern interiors, relaxes and adds character to traditional looks like provincial or hamptons styles. The wide plank will enhance the flow as a walk through, but still provide an intersting visual texture to the adjoining lounge area.

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.

I probably would steer away from black if you want to keep the country theme

I guess it depends on how much walking space you want. In this current configuration you have quite a lot of space for moving around, but do you want that? I would personally go for an L shape to maximise bench space with one section at a different height for seating. Alternatively, you could just have a standard L shape with seating on one side. Either way it's going to be quite a nicely sized kitchen.