I replaced my Garmin fuse with one from Radio Shack. Was the one you visited just out of stock or did they search their catalog and state that RS does not carry that size.
Mine is not hardwired, I use a cigarette lighter for power so perhaps the fuse is a different size. It was tiny, though.
Too bad you are at the other end of the state, I would offer you the spares that I have
2003 Suzuki Bandit 1200S