Changing projectile art trough items?

[Bane]

Hello everyone,
I am working on a zombie survival map (yes i know theres alot of them)
Anyways im trying to figure out how to change the units projectile art thru items.
Why? Because if the unit picks up a rocket launcher i want it to fire rockets not bullets.
Is there anyway to change the units projectile art from picking up an item.

Example: In dota when you get a mask of death it changes your projectile art to a crescent moon.

First person to help will be given rep,
Thank you,
-Bane

 

[Cokemonkey11]

Base it off any orb ability.

Note that orb's don't stack.

 

[Bane]

Thank you, +rep.