Bullets are easy - you want something soft enough to scratch easily with your fingernail, and the same diameter as the chamber mouths in your cylinder. Factory made? Tough to find any soft enough usually. That said, I have had great luck with the Hornady and Speer swaged bullets in guns with proper sized cylinders. Not worth a darn in Rugers and Smiths and their .433" holes!
As for .256 brass, if you're going to shoot it get some that have been made from recent 357 mag cases. I like Starline the best. The old Winchester stuff is too valuable to be shooting anymore, IMHO.