I was wondering if I am able to use Line 6 Monkey to make a custom tone for the Spider III HD150 head by chance? When I open up the Line 6 Monkey, I don't see the Spider available to choose for my input.
No Monkey does not work with creating tones, only updating software and backing up a bundle of tones of PODxt / X3 devices.
The Spider does not allow you to transfer tones on and off. The most you can do is save any presets you create to the user banks on the amp.