Awesome! Is there any online source which you can recommend for one willing to master a sling too?
I think you would find Slinging.org a good place to start. They seem interested in other historical and primitive weapons too.
http://www.slinging.org/Since they have an active forum they will be able to give advice and leads.
There actually is an international association that has slinging matches too but I don't remember their site any more.
There are some interesting videos posted on youtube by them.