Are you looking for someone to slice, and code your website design?
PSD to Wordpress: Professionals usually charge around $99 for the home page, and $45 per inner page.
PSD to Joomla, and Drupal are usually a little more expensive.
PSD to Magento: Usually starts at $300, and up but that is because there is more coding involved when you want a store CMS.
These are all average prices that professionals charge. You would have to be more specific on how many pages, if you want it coded into a CMS or not, and if you wanted your forums to match, etc.
cesisco is right there are a lot customizable templates for Wordpress, and you can easily build your own Wordpress theme. Just visit there site WordPress, and check it out. They have a friendly helpful community full of information, tutorials, and free themes. They also have many plugins like forum software that can be easily integrated into it.