Hi, I want to know if you can do a mocap of arms and hands to animate a weapon in the first person (fps).

Hi
Our software is intended for full-body mocap, and there is no special workflow for tracking of the arms or the upper-body only. For tracking wrist rotations you'll need to use motion controllers (PS Move). Fingers are not captured, but Mocap Studio allows to do keyframing for them.
When exporting animation, you can map to your arms/hands model only those bones from our skeleton which needed.
Unless you need a precise fingure capture, I suppose a single Kinect configuration (Express edition) may be suitable for your needs.

All rights, thanks