Most gunsmiths can handle a barrel chop, esp. if it doesn't affect the ejector housing mounts. The bonus is, you can now do anything you want with the front sight including a new custom base.
I would strongly recommend a barrel chop versus swap. You won't have to reset the barrel/cylinder gap. The only exception is if your gap is very large, out past, say, .007" or more. Then, a barrel swap gives you the opportunity to have that tightened up.
John Gallagher has shortened several guns for me to 5 1/2" Not that expensive and gives one the option of changing front sight styles or adding vertical white line or horizontal gold or silver bars if so desire.