I've been thinking about the plumbing solder.  I think the main advantage over other wire is that its a little easier to bend (I'm comparing it with the electic fence wire I use).  It's probably also a bit more commonly availabe around the world.  I would advise that you make sure you're getting the lead free solder.  It's no problem in the states, it not legal to use lead based solders in plumbing.  This is probably true in most other countries as well.  Sometimes you can find lead based soders for electric use so make sure what you're using is lead free.