Chapterhouse Studio gives you some more options with your minis with the release of their new Railgun arms.
From the release:
The Chapterhouse Studios “Battlesuit Railguns and Support Weapons” kit are a set of resin arm mounted weapons designed to be compatible with Games Workshops Tau Crisis, Commander and Broadside Battlesuits models.
Resin components sold unpainted and unassembled. Games Workshop Tau Battlesuit models are not included and are shown as examples of use only.
Each resin kit contains 20 components:
2 upper arms
2 railgun main bodies
8 rail gun accelerator components (to allow 2 different styles)
2 missile launchers
2 plasma guns
2 rail gun barrels
2 sensor antennae
I hope you like them.