I believe I found a solution to the 404 error. Inside the zip there is already a pandora. sh (i'm assuming for macs?). All you need to do is change the EXPORT to the wine temp location and remove the osascript line. Then run as a normal sh script to start pandoras jar and still use firefox with wine.
NOTE: I had to retype the script because I got an error about /bin/bash^M being invalid and I had no idea where the ^M was coming from.
UPDATE: I originally had my own script in a different directory, and got the error message as described in posts above. I don't have a clue why using