Ongoing architectural sketchwork

I need to find an artist that can convert rough concept scribbles into an architectural sketchy style. An example of an input sketch is given below with a couple of ideal output formats. Simple, quick, sketchy style needed - marker-pen type look with simple splash of colour, low on detail. Ideally you need some experience of interior architecture and current workplace styles. I need someone who can produce these ongoing for between £10 and £20 each.