Getting a PET as a terminal with the PETSCI and IEEE issues.
https://cbm8bit.com/8bit/commodore/disk-image/d4ddebb845d2ddd484f4d4953645dae1
and
http://biosrhythm.com/?p=1359

The PET has the same user port as the VIC-20 and C64, so I would think either the 
WiModem32 or Strikelink/Strikelink Wifi would plug right in. You'd just need a 
classic terminal program for the PET and you should be good to go.