My last 4x4 was a 99 SR5 Hilux that came with new BF Goodrich AT's. I sold it 3 years later with the same tyres after 70,000 km and they still had over 50% tread on them. They were like i had a strait road tyre on them and handled great. I spent only 5-10% of the time (5000km max) off road and on corrigated roads and they did me great. Can't speak highly enough of them. I've been told that if i were to spend a lot more time off road that the Coopers are the bees knees.
For your application I would definately go the BF Goodrich. Not the cheapest but great on peice of mind and they last for ever.
Cheers Chris