PGT your first option ( more like PPL > IR > PPL-ME > Comm.ME>Comm SEL > CFI > CFII) is better if you want to start accumulating PIC ME hours. You'll need the PIC time for the MEI anyway. On the other hand, it's a more expensive route to take, including two separate multi checkrides as stated above. I personally went for the second option because it made more sense financially in my situation, so choose whatever fits you best.
that way all the twin time i logged for my IR is PIC as well as for my MEC ride. I did my instrument in the twin as well. All i had to do for my MEC was stalls, steep turns, slow flight, and short field take offs and landings. Most people do every thing in a single so there MEC ride is alot of work. Not only do you have to do all the multi engine stuff, Vmc ext, but you have to do a single engine ILS to hold a Multi Instrument rating. and then you also have to do the commercial maneuvers. Not to mention that the oral will be quite a bit longer when you have to get into Multi engine aerodynamics in addition to all the commercial questions. Thats a lot of work for one check ride. The way i did it not only spaced all that work over three different checkrides, but i also started logging multi engine PIC very early on. My advice to you, is to get your ME add on asap, you will thank your self in the long run.