Yes, you need .sav files. Unfortunately, you need ENVI+IDL to convert .pro to .sav. It's pretty straightforward, though, maybe some kind soul would be willing to help. ;-) It would be a good idea to have both .pro and .sav files available to download from the library.
If anybody with ENVI+IDL wants to do it themselves, check out:
Just one of the many great tech tips...