CSS / XHTML Expert required urgently

We are looking for an expert at CSS and HTML to correct and rectify errors to make site cross browser compitabile and also to make few changes to design. The site is already coded and needs adjustments to the CSS codes. One the CSS / XHTML code is cleaned out we would like to user Page Speed to see how we can reduce the CSS codes and minify Java scripts to make the page load faster. Please note if you do not have the revelent experience do not bid for the job. We do not want to waste any time. Only serious providers bid for the job.