I've just finished the article on miniwargaming.com about Killa Kans. I added 3/16" magnets to the arms so all the arms are fully interchangeable. I was really surprised because at the end of it there was nothing left on the sprues... you get one extra gun arm and one extra close combat weapon (without the arm). That's it. I'm not complaining, since you do get 3 kans in a box, and if you get the deff dread as well then you've got plenty of weapons to make competitive builds... but it is a little different.
Check out the Kan article here
Check out the Deff Dread article here