I'm not quite sure what you mean by "include." You will not have "commercial multi-engine land" on your certificate. But an ATP has the same privileges as a commercial pilot with an instrument rating per 61.167. In addition they can be the PIC for air carrier flights and can instruct in airline operations without holding a CFI.
You could just get the SEL ATP and then the MEL. Your certificate would say "Airline Transport Pilot Single and Multi-engine Land. But you only need to complete two checkrides, one for the highest level SEL you want and one for the MEL ATP. The order does not matter.
Hard to say how much training. For the ATP 10-15 hours? The check will include a rejected takeoff and a low vis takeoff, you'll do some steep turns and stalls under the hood and hold. Two non-precision approaches, one straight in and one circling, one to a landing and one miss. And a normal ILS and two ILSs with an engine inop, one to miss and then another to a landing. A lot like an airline PC. If you do the SEL ATP you don't have to worry about the one engine inop stuff.
For the commercial coming off the bus I'd say 10 hours, maybe a bit more. It's all visual stuff, short and soft field TO and landings, VFR slow flight, stalls and steep turns, Lazy 8s, Chandelles and 8s on Pylons (I couldn't pass any of the last three today without a couple hours brush up.) And the engien will quit sometime during the ride.