what to use for a user rank based web application?

[eluser]Unknown[/eluser]
Hi there,

I'm working on a web app that is for a fitness community.
The goal is to allow users to post their favorite work out tunes and other users to rank them. sort of like digg and other web 2.0 voting based sites, but of course not as complicated.
I did some research and seems like CMS wouldn't be a bad choice? (i.e. joomla or drupal)
I also read some articles on flex today...
but a lot of mixed review on all of them!

what would you suggest? would it be easier to go with a CMS or write it in php, mysql (or whatever else db) from scratch?

ps. I'd rather use a template that comes with one of these tools rather than spend time on design

Thanks for your time,

parachuter2b