Id say the presa would be a good choice,it can withstand extreme heat,is both visualy intimidating as all hell and very apt to protect at the drop of a hat,they are perfectly capable of apartment living,non hyper,and a female will be less dominate and easy to socialize compared to the male, so all would be good..[also they can compete in all kinds of dog sports and activities,weight pull,p.p etc,witch is a plus] If you get a good dog[temperment,hips,health etc]there tuff to beat.. As for the bull mastiff,many are sickly short lived dogs with nervous skitish temperments,definetly intimidating but not athletic,they are heat sensitive also,fine dogs but hard to find a quality one,if you chose the bullmastiff go with the brindle dog.. Dogos are great also,but they unlike the other two breeds would be much happyer doing there job,[hunting] they are dogs with high prey drive also very sesitive dogs,probably not good for a apartment but good with kids[if from hunting lines]and better with dogs than the presa,they also can tolerate great heat extreams.. What ever choice you make there are good dogs to be found in all three breeds,but with the bull mastiff they are fewer and farther between..