The Pennsy had a whole bunch of everything! Your layout plan looks like it may have something tighter than an 18" minimum radius. If so, I would suggest you stick with Consolidations, ten wheelers, or moguls. John Armstrong had a treatise in the steam locomotive wheelbase vs. minimum radius I believe he called the Frustration Index. A Mike may work for you, but the rule of thumb is: small layout, small locos. They'll run better for you. You'll be disappointed and frustrated if you lay out what even an entry level model of an articulated steamer will cost you, and then it habitually derails because your radius is too tight. It's better to double head two smaller locos. Looks better too!