I agree with many of the other things said in replies, but would add a few additional points.

1) Know the legal status for Australia - Businesses want to know that they have recourse if someone stiffs them
2) Know how taxes would work - In the case of immediately exchanging via Bitpay, this isn't an issue, but ideally these shops would be able to start paying their vendors and employees with Bitcoins, in which case they need to calculate taxes on Bitcoin sales.
3) Research each business and relate benefits specifically to them if possible.  Being former salesmen I doubt you needed to hear something like this, but others might find it useful.

Finally, I want to join others in thanking you for doing this, it is exactly what is needed.  I would also be interested to hear how you make out, as I wouldn't mind doing a little bit of this on the side as well.