All pages will be php.
Database will not be very large, containing membership information.
I guess the mySQL will only be used for logged in user and participants in the competition. Images and flash will not call on the mysql, but will be hardcoded like a normal html-page.
Site has not yet been developed, so it's hard for me to speculate. And also, I am a layman
Um, the question is a bit like:
"I am building a store; some days there will be 10,000 customers, some days 2,000. What kind of bricks should I use?"
The server is a minor component in your service.
Get your application built first, using a low-cost server or your home PC. Then see what loads the application generates, and use that to define your server requirements.