Grant Taylor replied:

Brett, there are so many. My best suggestion would to be to post your question on this website
It's free to join but you need to be a "member" to access the forum. There are heaps of guys on there who live in that part of the world and could give you some great tips on spots. Needless to say the fishing up there is HUGE. Half your luck. Dreaming of a northern fishing safari.:~) Grant

sharon replied:

hi Brett, there is a nice little place called parrys farm which lies between Kunnunurra and Wyndum. To access this place you can use the track from kunnunurra to wyndum by way of Ivanhoe Crossing. There is good Barra Fishing in the Billabongs on the farm.
However be careful not to make camp along the river as this track prior to 2000 had been closed to the public for 20 odd years, so Crocs are a problem..... if you would like more information on this place and many other great spots then please contact me

My husband and I lived and travelled in the area of NT and WA for quite a while
looking forward to hearing from u