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.

Well it depends on your wall color as well . since you have such concrete looking floor I would recommend you can chose any electic color like lemon , orange , yellow to give a bright look and uplift room mood or chose any pastle color of your choice for subtle feel . :)

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.

Please advice