two forms content in one confirmation mail

[no_destiny]

I'm using v1.3.5.
I have two forms. In the first one I have three radiobuttons where the user must choose one of them and then press continue to come to the second form with all fields that must be filled in and then submit this form.
When both continue and submit buttons are clicked I get 2 confirmation mails.
My first qustion is how can I get all data from the two forms in just one mail ? (since the first form doesn't contain any personal information and I will never know who the sender is)?
My second question is how can I make the user choose just one of the three radiobuttons?
I can't set them to required 'cause the user then has to click all the three of them but I just want one to be chosen.

Thanks for any help