Originally Posted by Sly

Have you tried WordPress?

WordPress is really just a CMS. You can hack away all day if you know what you're doing. There are a lot of plug-ins and themes on the market that should be able to do what you want. Try that route, bring in a programmer to make the hacks that you need and keep the whole system light so it's not dragging for your members.

Be careful of security vulnerabilities and also unnecessary bloat. The programmer above should be able to help you with those.