I honestly don't know of any double action 45 colt snubs out there, that would be smallish. Seems like they all have large frames. 44 special there are a few. 45 acp I see there are snubs out there as well.
I like the single actions myself in 45 colt with short barrels, birdheads grips, ect....not that it would do you any good if your looking for really compact double actions.
I think because the holes in the cylinder are so big and long, we don't see many smallish double actions in 45 colt around. Most double actions in that caliber have pretty big frames it seems like.
For double actions in 45 colt, you might be stuck with just going with a short barrel, and do something about the grips.
OH...almost forgot....how about the Ruger Alaskan model? Have you checked that one out? 454, or 45 Colt?