Like cayuqad said, stick with the Steel framed revolvers because even if you do not chain fire it, brass framed models will stretch.

Either Revolver that you mentioned will be a fine shooterfor you but unless you intend to holster the Walker in a horse saddle or something I'd stay away from that one but the 1858 Remington, 1851 Colt Navy, or possibly the 1860 Colt Army would make a great holster gun for ya, I tend to like the Colt designs but that is my preference.

Pietta is a good manufacturer I have one of their 1860 Colt Army's & it shoots great, but Uberti & Cimaron are also good companies just a little more on the price tag.

If you want to do the conversion deal then the 1858 Remington would be a better suit because they can be obtained with the loading gate which makes reloading a bit more easy.