Wordpress theme to match current website design

I wish to add a Wordpress blog to our web site (placeholder is [login to view URL]). We have successfully installed the Wordpress application and we can create a blog in the default theme ([login to view URL]), but we wish to change the theme such that the Wordpress page neatly fits into the rest of the web site. This project needs to be completed today. Please only respond if you have completed a number of Wordpress theme designs. Maximum budget available for this will be $75.