Just a thought - Have you tested the existing cladding for asbestos prior to removing? Some of my coastal clients also feel the need to 'fill' the corrugations at the ends prior to capping or butting up to end frames: to dissuade small creatures from also moving in to a nice new home. Colorbond Surfmist will look great and horizontal will help to balance your homes height, however, it also gives ridges where dust and dirt sits and so needs to be hosed down more often - probably a good idea as it removes some of the salt as well. Good luck with the reno, the Architects image looks great.

Looks like colorbond or scyon wall cladding, concrete render painted white/off white and 'apollo' bricks by boral.

This is the inside of the house. The bottom photo is the inside of that extension. The House is a Yellowy Creamy colour that is very dated and we want to change to a more neutral off white at a later date. I did think that a white or off white for the outside might look a bit too white and washed out with the white Brick. The Brick does have like charcoal flecks through it. So maybe that colour could be good to coordinate with.

The silver will look quite good with your colour scheme. I would probably change some weatherboard for Scyon Axon just to change it up a bit. Also use Scyon Axent for architraves and wall corners. Don't forget eaves and veranda ceilings, etc. as a really nice looking feature use HardieGroove or maybe even some timber to break up the acres of painted surfaces.