Hey- I am looking for advice and suggestions for right arm bits for a series of space marine bike squads I want to put together.

I'm looking for right arm bits that would allow me to have my toops hold guns aimed forward or to the side. So far I have found arms from the assault marines (clip off the pistol, put in a gravegun/melta/etc) and arms from the sargent in a regular troop kit. Does anyone have any other bits from any other kits to suggest, or other ideas about ways to model a bike squad with upgraded weapons? I am thinking about gluing or magnatizing a gun to a biker's thigh to represent a mag lock or whathave you. The benefit of the magnets is that I could swap out weapons for different fights, the con is I suspect the guns will get lost.

Any and all thoughts appreciated. Thanks!

David