I am contemplating purchasing the Auto Reversing System #44847 for "N" Scale.  Since I have never worked with this system before, I am trying to determine if I need to go the route of a system or just purchase the components separately if they are even sold seperately.  I want to run a straight length of approximately 42" to run my trolley in the front of my platform.  I really don't need the curved pieces that come in the system, so would it be less expensive to just purchase the reverse track components separately and are they even available?  Also, is the power pack that comes with the system a special one designed for this or can a standard one work as I have several of those.  Also note that I am only running DC.  Any input and suggestions are appreciated.