Just for inspiration, as I don't know your budget, how about something like this? http://www.plainenglishdesign.co.uk/arts-3 or these http://www.neptune.com/furniture/bathroom/washstands-taps/ I find most off-the-shelf vanities in the UK are either hideous and cheap-looking, or nice but cost a fortune. Fired Earth is another that's expensive but has good country styles. I would probably get a carpenter to make something bespoke with a marble top. I'm having my bathroom cupboards made in moisture resistant MDF, but I want to paint them so it doesn't matter that they're MDF.

We've been for a look around a tiling store today and played around with some ideas. We really like the below tile, similar to what was recommended above; We compared it against a wooden effect floor tile, an anthracite tile, and a "cement" coloured tile; The bathroom itself is fairly small; approx 2m x 2.5m. Not sure if the wood or the anthracite might be too dark for the room?

Sounds great, go for it. Once the bath is the other way around, the room will feel less long and narrow as the floor space will be more square (or more short and wide rectangle really). Keep the floor on the lighter side and paint the walls and ceiling the same light colour and it'll also feel more spacious too. You could paint the built-in cupboard the same/similar colour to the walls so that it disappears visually and doesn't seem like a huge thing facing you when you first go in - get it painted in white undercoat first and see how it feels before deciding on final colour. But I'd definitely do the blue toilet/basin unit if you love that colour - it's a very easy colour to work with and it'll be nice to have something a solid colour. Another option is to go colourful/dark on the walls/ceiling as well as units and embrace the fact that it's a small room where you can be more bold with design choices. Keep tiles the same white as your toilet/bath/sink to keep it simple and then you can change paint colour without worrying about what you've chosen as tiles.

I think vinyl wrap as well.. You could paint the gloss doors if you sanded them well and prepped etc but it's so much easier to get them wrapped or do it yourself if you only have a few.