I wouldn't want it to be too finacially motivated, I personnally think prizes should be about the glory rather than more tangible assets.
I have no problem with people promoting themselves or companies at tournaments but I don't want rewards to be significant enough to cause any conflict.
If you follow the links from the "Blood Bowl Kubla Cup - The Street II" game entry on the Kublacon website, full rules are provided (although they are dated from the 2010 KublaCup). It looks like the 2010 edition was NAF-approved. I hope 2011 will be as well.
It looks like Kubla Cup is scheduled, I'll do my best to show up for this. I'm a bit confused, can streetbowl tournaments be NAF approved?