Chat Program (Online)

I am looking for a chat system to be made for my website. How it will work is on the page, there will be everyone who is online, there will be just one big group chat. Then you can PM eachother (usernames) if you choose to do so. The only way to sign up will be to request a sign up, it will send me the username, email, and email they wish to sign up with, they I will manually make the account myself, then email them if they are accepted. There needs to be extra features like there are on all other chat / IM programs (like skype, AIM, mIRC) Can be kind of like a mIRC design, it's simple but still custom. So overall, group chat, private messaging, customizable messages (smileies, colored text, default avatars) The entire thing should be on one page, the private messages will just be on like a tab on the page, you won't have to go to another page to read / reply to the PM, it's all going to happen on this one page. Thanks, contact me for more info on the project.