Looking to expand a Polar Express starter set. Adding track and a few manual switches with total track about 3 to 4 times length of starter set. Also plan to add a few more lighted cars, sound car, and a few accessories (eg lighted platform, lighted flag pole, gateman with activated track section). I like running the LionChief off of the iPad app. The starter set came with a 54 watt, 3 amp DC wall power pack. How many amps will the above be expected to draw? Should I upgrade to the 72 watt/4 amp DC power pack? I do like the DC power packs as they are relatively small and easier to conceal. Also, I was told I could hook both the 54 watt and 72 watt packs up concurrently - each to its own LionChief terminal track piece to increase overall amperage/power; is this possible?