Recommendations for how to build this site

I’m hoping someone out there could throw some ideas my way on how to achieve the following:

I want to create a site where registered users are all contributors who can add new posts. But, I want all posts to look the same with the same information. Essentially I hoped they would fill in a form and the data from the form would create the new posts. I also want to be able to search/sort the posts based on a custom date field.

The site would be listing giveaways from other blogs – so users would be submitting their own giveaways. I have looked at using a classified type theme (I even bought one) but they all seem like it would take a lot of additional programming to get them to what I need (ie I don’t need prices or locations or most of the typical classified listing fields but I do need the ability to sort posts by the day the giveaway ends)

Also I would eventually like to be able to charge users a fee via paypal to submit featured giveaways.

So I’m wondering if anyone knows of an existing plugin that would allow registered users to all use the same post template to submit their giveaways.

Thanks in advance – I am currently running this site in blogger and have to manually insert information into each post’s default html code and it is very time consuming so I’m hoping WP can help automate this process for me.