I'd get a full choke for the Beretta and the Hevi Shot, It will save you money and time finding 3" shells than 3.5" shells, I wouldn't go with a tighter constriction than full for hevi shot below #6, but if you're gonna use #6 and higher than I'd use a extra-full, only because the tighter constriction could effect the pattern of the load.

I'd say if what you're using now is giving you good patterns I'd stick with that "What's not broken don't fix it", I can say myself I really don't care for the Remington Nitro loads for the reasons that they are just plain lead shot and have poor penetration in my experience, I like the copper plated shot or even bismuth or tungsten.