Hi, I will have about 120 feet of 0-27 guage track going around the room on a shelf 8 feet up from the floor. What kind of power pack or transformer will I need for something like this? Would this be a large lay out or what ? I have no idea what to send away for. The engine is going to be a MTH 2-8-8-2 USRA STEAM ENGINE W/PROTOSOUND 2.0 - UNION PACIFIC. What should I buy. Thanks for your help.