Curtis,
Maybe you will find this reply handy. I have recently also just purchased a used Pod Pro unit. The only footswitch that I found that would work is the old school Line 6 Floorboard. Additionally, you may also be able to use a MIDI foot pedal. The manuals are still available through the support sections on the line.com site.
As far as software, you should be able to download a copy of the Line6 Editor. This is the software that I have found to work. I cannot remember if you have to create a login/register your hardware first...
Hope this helps