A lot will depend upon planned use. If you want it for a concealed carry, then the Buckmark or Ruger MK II/III may be too big for you. If for target shooting, then try out the grips. I have the Buckmark with a UDX grip (curve for the thumb -- URX has curves for the fingers).
Regarding the Bersa, I have the Thunder 380 -- and a word of warning about the nickel plated -- some parts start flaking off immediately. It happened to mine and today I dropped by a gun store and talked to the owner -- he said that he has seen the same with his inventory -- all calibers. So, if you get a Bersa, it looks like the nickel won't last.