For all your weapons and support systems magnetize them however you normally do your suits. As you can see from this photo I have 2mm magnets set up to accept any of the weapon or support systems.
I also have the same size magnets on the upper and lower side of the left arm. These are used for weapons if I want to show the support systems.
Last but not least The shield generator. This was done with 2mm magnets. Drilling holes in the center of the left arm. Clipping off the tab on the shield generator and drilling a whole for the magnet. At first I didn't think this was going to be enough but as you can see in the picture it works fairly well. If you slam your models around. You may want to go with the larger size.
Feel free to ask any questions. Or if you have any better ways of doing it please let me know. I am going to build a couple more.
So after a lot of painting. (still not 100%) I am really slow. I have the riptide to a point that I can show the magnets in action.
First shot is all the goodies put out in one big shot. Really like the way things are turning out.
Next up is the Ion accelerator and all the parts used in the magnetization.
Next is the Heavy Burst cannon using the same pieces that are used on the Ion accelerator.
And last the Shield generator.
Thanks and hope it helps.
10/1/2013 edit: Updated some pics for better focus.