i have good old fashioned mongrols in most of my hives, i do have some native black bee cross in 2 hives but it all depends on your location.
if you live somewhere that has really cold long winters avoid italians.
in the uk most of my hives are populated with locally caught swarms from feral colonies. they are perfectly adapted to their surroundings so do not need to worry about what type to keep, mother nature already did the selection for me.
its all about env/weather conditions in selecting your bees. of just get some local feral bees which are naturally adapted to the weather paterns.
nothing worst that installing bees which require lots of maintenance ayr