Hello, I'm still new to DNN, so maybe what I want is not possible??

Where can I find out how to customize the feedback module so I can have two more text fields in it, such as for people to provide a phone number and to say where/how they found our site??

Has anyone done this??

Or am I better off buying a commercial forms module?? If so, are there any?? The only one I've seen so far is XMod , are there any other ones??
 
I don't need a ton of bells and whistles, etc., just simple forms-to-email.

Thank you, Tom