Newsletter signup Form with URL as the Form Action

Can anyone recommend a form plugin that allows the option of having a URL behind the submit button instead of an email address?

When someone completes a newsletter signup form with first name and email address and presses submit i want it to load the url post it and redirect to the thank you page with something like this as the form action for example : lnk.abc.com?fname=<firstname>&redirecturl=abcthankyou

or maybe this will work just as a html form in a text widget?

Thanks in advance for any help.