Modifying 987.1 to have other horns
 

I don't care for the stock Cayman S horns. They aren't sufficiently awesome, like the second (ROW) horn in this video: https://www.youtube.com/watch?v=zsQftCK4Q6g

My understanding is that there are two basic approaches to doing something like this, once I have picked out the horn to use and mounted them:

1) use existing wiring
2) wire in a new circuit, add a fuse and relay and use the existing wiring to control the relay

With the first approach, I'd be concerned about overloading the circuit/wiring. With the second approach, I wonder where I would make all the connections.

As for picking the horn I go with, there is the sound issue as well as the electrical compatibility. I am looking at the Hella Supertones, as youtube has me beleive they are similar to the sound that I'm going for. I think they draw 6.5A, is that more than the stock horns?

Any help, or electrical specs on the stock cayman horns would be appreciated.