I wouldn't say the 10mm is exotic. It isn't the 9x19, but it still has a large enough dedicated fan base that at least half a dozen different manufactures load ammo of some type for it. Federal loads low-range .40 S&W level ammo for it, if their online ballistic charts are close to accurate, the Hornady and Winchester loads could be considered mid-range, and then there is the full power stuff from the like of GA Arms, TAC, and Mr. McNett at Doubletap Ammunition Company.
There is still a decent number of pistols for the cartridge as well--the EAAs, 1911 patterns from Brown and Kimber among, possibly others, you should still be able to find S&W autos, and then there are the two from Glock. I too am a .45 fan that has had my interest peaked in the 10mm Auto. If HK fails to impress me with their custom service, I will be selling my HK to get a Glock 20. Talking to several owners and handling them in person has convinced me it is an interesting and impressive pistol with alot of potential and possibly, at least on paper among the most advantagous combat pistol in existance.
Then there is always handloading...