Bushman 80% is the stuff that only comes in a cream, and that works for most things (percentage of DEET does not mean it works better, only longer).
I always carry tea tree oil with me for bites - it makes them disappear within a few minutes, and even helps with sandfly bites. I've heard that it is a great repellent too, though have never experimented with tea tree alone. Some people swear by the stuff, though.
We were just up Cape York and the sand flies were unbelievable. Without some tea tree for the bites, would have gone insane. My cameraman reckoned he was going a little crazy from all the bites...
Carlisle