Control Software development

I have a requirement for development of a program that will be used to control vehicles and other items on a model railyway environment. This will need somebody with experience of integrating software with an output to control low voltage Dc motors, LEDs, etc. I am thinking about development in Arduino programming as this is apparently well suited to this style of environment, and the hardware requirement for outputting signals from the program are readily available commercially. Please refer to the attached basic specification, and come back with your ideas, or experience of this type of work. At this stage it is an idea I am keen to develop for myself, but I think there may be more work if we can prove it worth pursuing in a commercial environment. Thanks