Puppets War has new cyber claw arms available over in their webshop to help mod your models.
From the website:
Set contains 5 claw arms (can be used as well as right or left arms) , parts have 3x1mm magnet type holes. Models are designed to fit 28mm “heroic” tabletop wargames scale, supplied unassembled and unpainted. Designed and sculpted by AR.