Like almost everywhere else...you'll be quite limited.
There appears to be a HobbyTown (north/central KC).
I have been out of that area for over 15 years now (Leavenworth...the town, not the "hotel"!) There wasn't squat back then either. There was one mom-n-pop shop, out in Lawrence KS, but really wasn't any better than what you'd get with a HobbyTown.