A bolt down lids is when the tank lid is bolted to the tank. This helps prevent things from getting into the tank.
Any model number that has a D like this will have an insulated tank. Any model number that has B like this will have a bolted down tank lid. The Angle Supply is the part on your floor or wall next to the toilet that allows you to turn the water on and off. If you are replacing your existing toilet you will already have one of these.