Wordpress - sign up to newsletter using custom form

Hello BHW

I have a website that I need to add a newsletter functionality to. I would like to use an existing newsletter plugin or something similar, as coding my own would be too time consuming. The problem is that all the newsletter plugins that I can find have their own custom forms. I would like to be able to make my own checkbox and using PHP to pass a signup-parameter to the plugin.

Do any of you guys know of a way to do this?

Thanks in advance

What mail server are you using? If mailchimp, aweber you can select the codes and use it on your site..

I was thinking of just building a list and sending the mails through plugins (with no external mail provider)
But if mailchimp and aweber have easy integration, that might be the best option