Doug..it's PSK-31, not 32! Most all of the software is free. Probably the most popular PSK-31 software is called DigiPan. There are numerous PC to rig interfaces, most, in my opinion, are overpriced. One of the simplest but most functional you can buy from Lektrokit for $16 bucks. It has everything you need to interface your PC soundcard to your rig.
A great place to start looking is www.qsl.net/wm2u/
That will guide you to both DigiPan and to the Lektrokit web sites.