Tractor rental costs here are well over $100 per day. I would be better off hiring an experienced local operator with a small tractor. I have not driven one for about 20 years (used to brush hog some). With our usual traffic and the distance involved it would take a couple hours round trip to go get one and almost as long to return it.
If you do decide to rent a machine and operate it yourself, check with them to see if the delivery/pickup costs are more than the hourly rental fee you'd be spending doing the pu/delivery yourself.....
I agree on the forestry head, and getting an operator to do it for ya. If you make a mistake, wrap the fence on the head, you will spend a lot of time getting it cleared.
Tracy, send me a PM on what they run down there. I'm curious to price compare to up here.