Swapping between weapons within an isometric.

I've been trying to create certain weapons that spawn across the map is set spawnpoints. I have the spawnpoints down, however, I'm having trouble in the creating something that when picked up changes the gun into a different type (shotgun, sniper rifle, assault rifle, pistol, etc.) so, I was wondering, how could make an object change gun raycasts (shotgun), damage and range (sniper rifle), and speed (assault rifle)?