General Site Improvements

I created a site using drupal 7. This site is to provide diaries for certain groups. It supports private and public blogging. I need an experience drupal guru who will organize the site and create a better theme. New improvements include: 1) Improve site look and feel and create a better landing page. The landing page will has few snap-shots from the site that tells the visitors about the site. 2) Make the site run a bit smoother. I've receiving errors for example: I can't access the appearance area for some reason. 3) Create a pro-user who can have more functionality than free users 4) Create a way to receive annual membership