OSB board will do the trick. You need another photo for us to offer a species and finish. Natural finish (clear coat...water based polyurethane finish...NO oil modified) in a low gloss or satin finish on white oak with FLOOD LIGHTS will offer the same "look" as the poor photo. Beyond that, you will need a better photo.

It totally depends upon your interior theme. Now a days polished cement floor is in as it gives quite a raw look and you can go for some combination of glass mosaics with it. Else you have so many options readily available in the market.

It depends on the overall theme of your house and if there are any special requirements for either marble or wood. Wood is softer to tread on than Marble and Marble is easier to clean.

Hello. As you rightly mentioned, there are lots of varieties of tiles available in the market today, including the wooden pattern ones. These designs are offered by almost all the leading tile companies. Well, the patterns/designs are usually on individual's preference, but a natural teak wood pattern would give a natural look as you requested. More than the designs of the tiles, the points that I would suggest to take care of before choosing a pattern is 1. It should not be too dark as it will make the room look smaller 2. It can have a decent amount of texture finish, but shouldn't be over board as it will be a hindrance to walk freely and also cleaning would be a pain. 3 The thickness of the tile, many good companies be of standard quality 4. Easy availability of the tile, in case you have to replace the broken tiles, they should be easily available. About matching the floor with your walls and ceiling, do not replicate what is on the floor (color/pattern), instead go for something lighter in shades (wallpapers or paints) for walls and for ceiling you can consider the wooden theme PVC panels, which are available in multiple colors.