I think that ceaserstone or marble would compete too much with your tiles and could look odd because of that. In the examples you provide, the one lot of marble stairs are with a very plain tile and the other looks like it matches the floor exactly. Your tiles have a bit of a swirly pattern so unless you chose a very plain stone/marble it would clash IMO. Also, ceasarstone can chip and I don't think it would be a very practical option for stairs. Timber would add a bit of warmth to your whole sleek look while still looking modern, and be something to tie your front door in with so it isn't the only warm looking thing in your whole light coloured area.

I'm a big fan of black as both a statement and accents (e.g. high gloss kitchen bench tops and splash backs, matte black main vanity and floor tiles, lounge, Art Deco sideboard etc). It seems to collect and show dust on the floor more than most, and can suck a lot of light depending on its location and application. Why not 'test drive' your black flooring idea (cheaply) with some wide black gardening plastic from a hardware store for a few weeks before committing to an expensive and potentially irreversible step. The plastic can always be used as a drop sheet later! You may find that having your black in furniture (such as Japanned table or sideboard) and accessories, together with the odd touch of jarrah, may be the look and colour balance you seek.

Hi why don't you install the spotted gum floor on the staircase? you can just order a plain staircase from the stair company, and the flooring installer is able to lay spotted gum floor on the staircase. The stair nosing can be customized by using the same spotted gum floorboards. That way you will have a flush finish through the house space.

Hi siriuskey. Not sure how to place the furniture yet. Still trying to work it out.. I am selling my dining table and chairs. My new chairs just arrived today. I bought some hooks to put my mirror up.I am going to order those prints shortly. Also trying to find a round dining table I like. Getting there slowly : Thanks for asking. Thank you Julie. Very kind of you. :) Thank you legendaryflame :)