I've got a stainless Camper UFX, just like the one in Sigarms228's pic. I've had it for about 5 years. I replaced the black front post with a Dawson FO front sight. That helped a lot.
As for ammo, I've run only Aguila high velocity copper washed roundnose and Mini Mags without any malfunctions. The gun has a great trigger, and I like the adjustable rear sight.
As for something you should know about the gun? If you're into detail stripping when you clean, like I am...the Buckmark will probably present the biggest challenge of your gun enthusiast life. I'll typically fire 1000 rounds or so through the Buck before I decide to clean it. There is soot and carbon fouling EVERYWHERE. It might be a personal character flaw, but I can't put away a dirty gun.
I found a YouTube video that another brave soul had posted which demonstrated him detail stripping a Buckmark. Suffice to say, it is not for the faint of heart. I'm a patient and mechanically inclined individual; a large part of my career dealt with the repair and adjustment of very small and precision mechanics. I'm not often scared away by a challenge. I watched the video, studied the gun, took my time and took a lot of pictures during the disassembly process. I got the gun apart, cleaned and reassembled, and it still worked without any parts lost or left on the table. But, I certainly did have a sense of accomplishment after that.