I have a Gammill and have found that the service has been great--my "local" rep is on my speed dial and never fails to answer questions and get problems (haven't really had many) resolved. They are close enough that I've had them do little maintenance even. The one time that neither of us could figure out an issue, they sent me directly to the factory (West Plains, MO) and Ken walked me through the issue and sent the part and then we talked via phone and got it installed. Point I'm making is that most of us don't haul a long arm into a repair shop like we do our DSM, so excellent service via phone becomes VERY important and also means that you don't have to have a dealer next door.
Gammill dealers will sell timing tools, parts that typically will wear out with extended use(like switches, bobbin cases & parts, etc). See you are in Rexburg , ID--long way from KS, but there will be a big show, KC Regional Quilt Fest in Overland Park KS (KC suburb) this June 15-17 and I think all the big long arm folks will be there.