Had a quick look at FPC Pro. I really do appreciate your response, jeanfabre. I kind of feel lost sometimes. I understand 3D modeling more than anything else and I found a solution by moving the weapons in animations. I simply positioned my secondary weapon behind the player controller, then made an animation where the weapons switched positions.
I wanted to use my own models and movements anyway, rather than using something like UFPS or a similar controller. I am pretty much a non-coder, hence my reaction to your question was 'weapon manager' what's that? (since looked it up) although I had some idea about destroying game objects and instancing new ones.
Anyways thanks, again.