TIMPIX, since you plan to have two reverse loops, one at each end of the interconnecting single track the wiring will be a bit more complicated. The products for which Banjoflyer posted links are the right ones for your layout. The easiest solution is to have both turnouts throw in unison, that way you only need to change the "polarity" of the interconnecting straight. There are two requirements then. First each loop and the interconnecting track must be longer than any train you run. Second, a train cannot be on the other turnout when a train enters a reverse loop. If you will be using Legacy I recommend you watch the Lionel product video that shows how to connect the Legacy signal to both rails of a two rail track system.
Were this my layout I would build this inner main as a dogbone rather than as a pair of reverse loops. I limit reverse loops to instances where I want a train to run in a different direction on the layout. If you plan to run any Gilbert operating cars reverse loops complicate and limit where and when they can be operated.
