rc-smart and walkera motors, they're all the same. By the looks of it, all these items you see online and ebay, they're all made by the same company and just rebranded by their sellers/distributors.
"RC-Smart" is nothing but a re-branding.

You can find alot of the same motors and speed controllers under various names

RC-Smart, E-power, Tower Pro, Electric Power, etc.

Just about all modern brushless esc's and motors should work with eachother unless you're trying to combine sensored and sensorless (which there is few of now anyways, just about everything is sensorless now).