Just to clarify: the carloop library supports GPS. There are a number of different GPS units that will work with this library, including the Carloop GPS. This support built-in makes it a lot easier to program your Carloop and GPS together.
One caution: there is an issue using CANbus and Serial (to GPS) with Particle system firmware 0.7.0. It is recommended to use firmware 0.6.4 if you need to use GPS, or you can experiment with one of the 0.8.x release candidates.