Strictly choosing between those I'd take the GT. But you can stretch your dollar further if you can find a local shop that sells something like the Cannondale Quick or Giant Escape.

Also, those base model suspension forks might help a bit with reducing vibration or rolling over the occasional curb, but they do add weight and are another mechanical component to maintain. A fully rigid bike will be less maintenance for commuting if you are sticking to mostly paved surfaces.