Custom Wordpress Theme

I want a new theme for my blog which can also be shared with readers. I have a budget of around $500. I'm looking for something that is clean, fresh, professional and modern looking with a good use of colours and shading. It also needs to be very fast loading i.e. low on graphics, be SEO friendly, have clean code and full browser support. I've attached some ideas I had this afternoon to give you an idea of what I want, but I really want to utilise the creativity of the chosen designer as much as possible. I've also trawled a few themes this afternoon looking for more ideas: * [login to view URL] - love the colour scheme and the white spaces * [login to view URL] - I like the top nav and the way the search engine is tightly integrated. I think to keep the top bar thin the search box will need to default to searching the site, but still using the google search engine, and then on the results page an option is given to search the web * [login to view URL] [login to view URL] -like the colour scheme * [login to view URL] [login to view URL] - like the title colours and the background shading * [login to view URL] - gorgeous colour scheme, nice use of different coloured blocks to break up sections * [login to view URL] - love the use of blues