Seems this should be relatively easy.   I could not find any pre-made
silent ringtones, or maybe just a single tone.

I want a silent ringtone so I can assign to the annoying person who is
calling me often.  I just got Vision, so I can use the internet to
download.  and I have no data cable.

Can anyone help me with this?  What process would I go to get such a
basic ringtone into my phone?

Thanks!
DougB