Graphic Design Enhancements to a Pre-Existing Website

I am in the process of creating a website on moonfruit.com. It is in a creative field and I have strong aesthetic views - but if a designer was able to offer enhancements (possibly including logo design/lettering/colouring etc) that subjectively appealed I would be happy to pay up to a maximum of £200 for significant improvments / additions to its content - and/or logo design for letterheads/and business card design. I can only consider commissioning someone who has an existing portfolio that appeals aesthetically - but if you have completed work of this sort I would welcome any examples of your previous work along with a quotation specifying exactly what would be covered by the price.