hardtail,hydraulic over mechanical?

Gidday, from nsw,my name is ploww and i'm very new to this so please pardon my ignorance,hope you're all doing well. i live in the blue mountains and have recently discovered the great times to be had on some of the local tracks,i ride an apollo mountain bike that seems alright,but i always buckle my back wheel on the more rugged tracks,also the brakes aint so good when it gets steep.i'm wondering about buying a new hardtail rather than a dually as they seem a little cheaper also mechancal discs over hydraulic for the same reason, a local bike shop has a sale at the moment on norco bikes.i would really appreciate any expertise and guidance forthcoming on hardtails,brakes,norco,etc. i rode the oaks fire trail on the weekend, its rugged in places and its the sort of thing i would like to get into,i wonder if the kind of bike i've mentioned is suited.
thanks heaps