Customize and implmentation of Wordpress Vantage theme, migrate existing directory

I own a well established web directory that I want to convert over to the Wordpress/Vantage theme platform. [login to view URL] The site is currently built on a popular php/mySQL directory script. I need a developer than can help with this process and do things like: 1. Modifying/customizing the existing theme as a new child theme to create a unique look for the directory. This will include styling changes, modifying layout, adding/removing elements from the existing theme. There will be modifications to the submission form and packages 2. Implementing a screenshot system, that will automatically take a screenshot of each websites submitted to the directory. You can implement an existing plugin if you can find one, or create a system for screenshots. 3. Creating a robust email system to do things like: send automatic emails upon new submission with upgrade links to upgrade to featured status, send auto emails to renew listings that are expiring, send auto reminders etc. (the renewals and reminder emails can be set up to run once a day on crons, the submission emails need to be send in real time). Not sure if the Vantage theme has email templates that can be modified. The existing directory has all these scripts in place, you might be able to modify that code for wordpress. 4. Transitioning existing site. Importing the 50,000+ listings in the mysql database into the new site, while preserving the link's expiration dates, featured link status etc. This can be exported in to a text file, there are no images or media to transfer. I would like to find a long term contact person that can work on my directories. I own several more than need to be also converted, if this one goes well. I am looking for someone at an expert level in Wordpress, PHP/mySQL, no amateurs. Must do professional work with 100% usabilty and clean code.