For Buff it will be the NT, the top half. For camel its the NT, lower half and some parts of South and Western Australia. Dingoes have been put on the protected list in the NT, not so in Queensland. In most areas with buff they will have pigs, donkeys, scrub bulls on offer, as well as some good barramundi fishing. I've never hunted with a guide so can't comment on who's the best etc, but here are some guides taken out of a Aussie hunting mag.

www.worldwidehunts.com.au

N.C. Trophy Hunting - Nick Cherepanov-
Ph 0408233268 (you'll have to find the country code)

www.ozziehunting.com

Muckadilla Safaris
muckadilla@optusnet.com.au

Davidsons Safaris
dassafaris@onaustralia.com.au

Hope that is some help.