First of all, welcome to the forum.
Second, Bill is right. There is no need to run two separate buss wires. Railpro will work on any DCC-powered layout without any issues. You'll find that Railpro is far more capable than it first seems. 14 volts is ideal, but I've run Railpro on lower voltage without problem. The starting and top speed will feel a little different with a lower voltage, but it's totally usable.
Just put your Railpro locomotives on the track and have fun. It's that simple.
-Kevin