What sort of tent should I take on Overland?

Hello Im planning to do Overland in September. Im relatively new to trekking and need tent advice please...I really dont want to spent hundreds of dollars! Has anyone just used a cheapy which did the job? Some people have told me it might be better to sleep in your tent even if the huts are empty because it will be warmer in the tent as the heat is kept in. Does this sound right?
Also Im curious if the bunks at the huts have mattresses? Just seeing if I should invest in a decent inflating sleeping mat...
Thank you everyone!
Also Im curious if the bunks at the huts have mattresses? Just seeing if I should invest in a decent inflating sleeping mat...
