I don't know about spare spools for the reel. Gary is away at the tying show in NJ. After that he and Nancy are going to Washington state for two weeks with Jason, Kelli, and their new grand daughter.
Good choice on the fly rod. I actually have 2 of the Pro Series 4 wts. I bought a spare backup. The $129 is less than I paid for the rod through Gary.
I also have the LT rods. When Gary was designing the Pro and LT series of fly rods, he said the 8.5 ft, 5 wt LT was the best 8.5 ft 5 wt rod he had ever casted at that price point ($300). Gary Loomis also test casted the fly rods and said he could make a better rod but it would cost twice as much ($600).
Here is a photo of Gary in his back yard when we test casted these rods. He is casting an entire WF 5 line with the 8.5 ft 5 wt LT model. I ordered the rods from him even before they were released and I got my rods before the Fly Shop did.
Gary uses what he designs. Here he is with a smallmouth that caught while fishing at our lake cottage.
These are photos from Gary's September trip to a Wisconsin Lake Michigan Tributary for Browns and King Salmon.