There are many examples on houzz of contrasting counters for perimeter and island. For example butcher block on island and stone on perimeter or a solid color on one and something with movement on another. I would only mix two stones if one had movement and one was fairly solid. The stainless on perimeter and something else on island sounds good to me. Here is a pic of stainless counters with what looks like a stone breakfast bar. (I hope I understood your question right). http://houzz.com/photos/3137660

I have just taken a couple more pictures (excuse the untidy house) from the stairs. As you can see it's an open plan area that isn't that big but very high ceilings also in wood (Macrocarpa) with dark wooden beams. The house is surrounded by bush so quite a dark house. I initially considered a darker wood similar to the beams but not sure if that will make the house appear smaller / darker...I'm really not sure what to do!?!?!? Thanks

Absolutely no problem changing up the carpet. Things to watch for......make the transition in a doorway, an opening or along a visual break in the rooms (like the corners of the walls). I would stay in the same colour range, but just go to the other end of the spectrum rather than change the colour completely.....like light grey going to dark grey, not light grey going to navy blue. You want the separation but an easy transition on the eyes.

Get the professional sander guys in to repair the living areas and kitchen but don't go too dark with the stain as it will kill the lovely grain in the matai. I'm thinking a couple of tones richer than the timber knots showing in your photo, definitely no yellow tone at all. In NZ stepping on to carpet especially in a kiwi winter is so much nicer than a cold floor board shock!!! A nice area rug for the lounge and you're done.