PDF forms

A client of ours sent us an IRS (W-9) form as a PDF form.  Don't have
a working printer right now (mechanical issues) and thus can not
print, fill out, sign and then rescan to send back.

Is there anything in the ports collection (or anywhere else) that can
handle both filling out the form and superimposing a scanned copy of
my signature onto it?

For the last part I guess I can use GIMP but none of the PDF readers
in the ports collection I have tried can handle both filling out and
saving PDF forms.

-- 
Aryeh M. Friedman, Lead Developer, http://www.PetiteCloud.org