In New York with an overweight permit you can run 102,000 on 5 axles or 107,000 on 6 axles. The older permits were for 120,000 on 6 axles, now they are saying they are going to change that to 117,000 on 7 axles in the near future if you want to replace a truck with a 120,000 w 6 axles. All lift axles must be steerable on anything 2006 or newer. Most of the bridges going through the city are 80,000, the max is 105,000. Number of axles and overall length is how they figure your total weight. Every foot makes a difference. As far as a lowboy goes im not sure exactly when you start moving really big stuff.
PDUDE, I think your best bet would be to get your CDL and a truck and trailer with air brakes. I dont think you'd be legal with a 120 and no CDL anyway because of your overall weight. What you would spend on a truck and trailer with hydraulic brakes might be less in the beggining but in the long run it will cost you more, and if you plan on getting a CDL anyway, might as well start soon. Some truck driving schools make it quick and easy.