You can not play FOOK2 and FWE at the same time. Both mods are overhaul mods, this means they both change lots and lots of things in the game...put them together, and you will enjoy a nice game of crash :ahhh:
Actually, you can. I am. But, it requires quite a bit of tweaking in FO3Edit. And, since it isn't a simple process, I'm not going to get in to the details of how it's done. http://www.gamesas.com/index.php?/topic/1096880-fwe-and-fook-2-patch, but I'm not getting in to the mess of trying to help someone do it again.
As for the OP, the FOIPs for WMK is an either-or deal. You can either have mod kits for the FOOK2 weapons, or for the FWE weapons. Not both.