a 36" sink base does not mean you have 36" available for a sink. The measurement is the outside measurement of the cabinet; this there is typically 5/8" thick walls on each side of the cabinet leaving 34 3/4" inside dimension available for a sink. Keep in mind you have to fasten the sink to the top and thus need to accommodate for the fasteners as well.
So how do you decide on what sink will fit what cabinet? Typically Sb33 and larger will accommodate most double bowl sinks. Anything smaller will have to use a single bowl or drainboard sink.
But the sink I want is too big for my cabinet??? A industry accepted practice of cutting the sides of the cabinets to allow for a larger sink is done all the time. Ask your designer/cabinet person if this is an option... you will not see the cuts unless you are inside of you cabinet.