Gun- too personal for me to recomend. Only you can answer that question by "feel". I like short barrels for fast shooting. Them Beretta/Uberti's are some fine fine pistols.
Bullets- soft lead ONLY, heavy and SLOW. Very slow to allow follow up and keep splat down and they WILL chrony your loads (I hear) if they suspect too hot so, be prepared for that. The action is really close so....
Getta ton of ideas here...
"The minimum standard for center-fire smokeless ammunition used in all SASS matches
State, Regional, National, International, and World Championship Competitions is not less
than a minimum power factor of 60 and no velocity may be less than 400 fps. The maximum
velocity standard for revolvers is 1000 fps. The maximum velocity standard for rifles is 1400
fps. Pocket pistols, derringers, and long-range rifles are exempt from the power factor and