I see that you are an experienced owner and are willing to commit to maintaining even a large breed of dog like the ones mentioned above. I request you to look to get an Indian breed (either a Bully Kutta or an Indian Hound) because I own one and trust me when I say that these dogs being indigenous are completely adapted to our climate, food and environment. They are excellent companions will fight to the death to protect their home and family and require very little maintenance. The less said the better about their loyalty and love.
If you live in a bungalow or are willing to exercise your dog well I would recommend any Indian breed. Visit www.dogsindia.com
or other sites or even this site and look up breeds like the Rajapalayam, Kanni, Chippiparai and also visit www.indianmastiff.com
for more information.
Hope I helped.