Help determining name of plugin I'm seeking

Hello,

What I’m looking for is a plugin that I can use on my site http://nigerianblogawards.com that will require people to register their (nick)name, email address and IP address before they can fill out a nomination form for our 2011 awards. Similarly, I’d like those people to also be required to login before they can vote later in the process.

I would greatly appreciate it if someone could point me in the right direction regarding setting these features up and if there are plugins that can do these things.

Thank you in advance and please let me know if you need more information.