Hi Heinrich, lucky you, my favourite stream the Bushmans, from a fishing perspective you can fish in the reserve, just buy a permit from reception, we normally fish from the gate to cascade pools, should take you couple of hours. Before you enter Giants Castle nature reserve you will see private waters that belong to the hatchery, you can fish that water if no one is staying at their accomadation. Speak to the owners first before you fish they will charge you to fish. There is also tribal waters before the hatchery as you drive to the nature reserve but i've never fished it before.
September might be tricky if the rains dont come so be prepaired. a 3 weight rod and floating line will do, tippet wise fish the lightest you can, 5x - 7x will do, flies that i'd reccomend Dry - RAB's , Parachute Adams , CDC & Elk and hoppers. Nymph - small GHRE and Zaks.
Good luck and pls post a report.