So many options to consider
for your price range a good second hand Toyota may be just out of reach, however Nissan's are a very good 4x4 as are Pajero's. I wouldn't worry too much about fitting a snorkel. CB radios are great if travelling with another vehicle.
As for a tent, if you want to go that way, a canvas tent is a must for prolonged use and you MUST be able to stand up in it, a trip into any camping store will give you some great ideas.
You will also need a stove, 3 way fridge - one that is powered either by electricity, gas or plugs into car cig lighter socket - (much better than an esky), a bush shower and a tarp for cooking under. When you erect the tarp ensure that all guy ropes are spring loaded, that is at the base where they connect to the pegs, have a spring between the rope and the peg.
I'm not sure how adventurous you want to get, so I will leave you to consider these for now.