need plugin choice advice

Hi all

I have a site for a local farmers market. I went the vendors to be able to login and update what they are bringing to the market each week.

Currently we add a blog post(s) about the market each week, mailchimp picks up all the new posts and sends out our newsletter.

Getting the vendor info is a manual task and stuff falls through the crack. (and then the vendor whose stuff didn't get in the newsletter calls to complain.)

Is there a plugin or combination of plugins that I could use to give each vendor access to edit or create their weekly post? Would you create a template for each of them? Should there be one post that each of them edits a bit of?

It sounds a bit of overkill for a farmers market but I think doing this would be a good exercise for me.

Thanks
Lori