I was up there a few months ago and had no luck with the barra on fly, caught just about everything else (sootys, archers, catfish, tarpon) on fly though! We got a few nice big barra (one solid meter fish) on spin gear and a whole bunch of rat barra in the drying pools of the Dunham river. Absolutely stunning part of the country.
Do yourself a favour and take your light gear with you too, the amount of big sootys, archer fish and tarpon in some of these pools in ultra shallow water is staggering and I had so much fun catching them and seeing whole schools of fish chasing a fly
We fished el-questro and only caught small sootys/archers (do yourself a favour and get a private camping spot there, its an awesome spot) we and also fished at home valley station and caught absolutely nothing but saw some awesome sights and a very very large croc near our camp site. I think having a boat will make it much easier for you to catch quality fish though.
Hope you have more success than i did, and i still had a blast
-Dave