Well, actually Five senses IS now based in SA (along with perth and melbourne). Granted, it's only new to SA, but their presence is here to stay.
And as for other SA companies putting up the sponsorship, it's really a catch twenty two. In recent years Rio has been a major sponsor, only to receive crap about it when a barista using rio coffee has won the title. The same is true for five senses in perth and veneziano in melbourne. So it's really a hard fence for a potential sponsor to sit on.
Usually sponsoring such comps, a company has a lot more to lose than gain. So it takes a lot of balls to willingly put forward sponsorship, knowing that if one of "your" barista's does well you'll have acusation after acusation thrown at you, and yet still decide to put forward the commitment.
I mean look at it now, five senses (2nd major sponsor, only to AASCA) have put their hand up to help and here you are complaining already that they're not south australian and that that's the reason why your not entering. See what I mean, it's a tough gig.
And Aroma fresh (SA), while not an official sponsor, has clocked up many many hours in the organisation of the competition, and will recieve on thanks or mention for it (thanks bill!), and beleive me, there are many others.
And as for willing SA companies, the fact is, there aren't. Every year the board tries to obtain sponsorship from as many coffee related (and even non-coffee related) companies, only to be continually turned away. And this encompases most of all of those "proud to be south australian" roasters.