Hi Hayley
I lived in Doonan for nine months so know a little bit about the area. I still live in the vicinity and can maybe advise a little on the surrounding area.
I never saw any snakes in the time I was there and I was living on acreage surrounded by forest. Not saying they aren't there but then snakes live all over Australia. If you have any pets I would be more concerned with paralysis ticks. My vet told me Doonan is the paralysis tick capital of the sunny coast. However in my short time there I only removed a couple of bush ticks from my dog and nothing more sinister. Personally I don't like Doonan very much and I think the area is overpriced for where it is. Hence which is why I moved from there.
Let me know if you need some help on the area and I will pm you.
Debs x x