suffixes on small parts refer to some specification in the data sheet... Temperature, case type, lead materials, etc. Either should work.
If the zeners are hot, you have miswired something! Disconnect, and recheck. Go back to rancidbacon's article and double-check.
http://code.rancidbacon.com/ProjectLogArduinoUSB
Check out these working projects:
http://www.obdev.at/products/vusb/prjobdev.html
Please, if you are not an advanced experimenter that understands electronics, you should not attempt mucking around with your PC USB... YOU CAN DAMAGE THE PORT.
Ray
PS: drivers are HID and are part of every Windows base package.