I have 5 ROA's, 7 1/2" SS AS, 7 1/2" blued AS, 7 1/2" blued FS, 5 1/2" blued FS and 5 1/2" SS FS. All of my ROA's have both Taylor and Kirst conversion cylinders in 45 acp and 45 LC for each one. Being 3 screw frames you load 5. I have 3 Uberti 1858's, 5 1/2" blued FS (Kirst converted with both 45 acp and 45 LC with loading gate), 5 1/2" SS FS (Kirst converted with both 45 acp and 45 LC with loading gate). The conversions only have 5 chambers as the 6th is a designated rest for carrying safely. 5 1/2" blued FS with a designated Taylors 45 LC and 45 acp cylinder. 6 cylinder chambers on it but it has safety notches. I won't put anything but lead through the Uberti's as the BP steel though milled is not tempered.
I will shoot jacketed through the ROA's as they are same as the Blackhawk's. Being conversion cylinders, obviously you don't wan't to shoot "hot" loads, but they will take what is appropriate for their use IMO. I have a 357 BH and a Single six and a single nine, I do really like the versatility of being able to shoot either LC or acp through them. The ROA's were selling for ridiculous money for awhile until recently when they started making limited runs of them again. Still not cheap by any means. There's something about a SA revolver.
I think your focus on getting a Uberti is a good idea. The Pietta's frames are investment casted where the Ubert'is are milled and the inherent strength in the milled is noteworthy.