Website - Design Only - Nothing Fancy!

Right, this is a pretty specific one, but I'll be as concise as possible. Here goes. I run a small website making business that began as a hobby but is now starting to bring in a lot of projects. The websites I build are almost all Joomla. I am well aware, however that my strength is not in design - I can't make things look good very easily, and I'm rubbish at coming up with design ideas. I do however want to make custom designs for my clients. I'm looking for someone to design a website look-and-feel based on the brief I give, which I will then take and turn into the template design for the website. PLEASE NOTE: I do NOT want someone to design a whole website, just produce the initial mock-up of something that looks good and works well within the specific parameters of the brief, in order to inspire me and give me something to work from. This is by way of an experiment - if I get some interest there is likely to be a good deal more work where this has come from...