Sorry, this is an indirect answer to your question, but if you're painting the floorboards white in order to make the room bright and airy this may not be the best way. White walls will do more than a white floor to make the room feel airy (use brilliant white rather than normal white to avoid a cold feeling - I learned this myself by accident).
Re the bed, I think you need to decide on a style (e.g. divan with headboard, wooden bedstead, metal bedstead etc) before you decide on a colour. And don't forget that whatever bed you do get you have an endless choice of colour of bedlinen (which is also cheaper to change, and can of course itself also be white).
And finally, if it's airiness you're after don't forget mirrors - mirrored wardrobe doors, wall mounted (e.g. full-length) mirrors and dressing-table mirrors. Also, framed pictures with glass will reflect and bounce light around, also adding to the airy feel.