How does one digitally 'sign' a pdf document?

I want to place my signature and that of my wife's on an estate agent's sole mandate form which is in pdf format.

I have Adobe and Acrobat and typed in the details on the form. I also managed to 'sign' the form digitally messing around with a handsfree mouse but this is awkward and the 'signature' doesn't look like my regular signature.

I can type in all the form's details, print the document and then sign it in the usual way, then scan and email it.

Or is there a USB 'pen' I can buy to sign the document/

Thanks

mafioso