LOL
I just finished a 1.5 acre job just like this last week (rough terrain). If you have to underbrush, do that first so you can see and so you don't have to fight wood and brush through it. Rent a billygoat mower (walk-behind bushhog) and clear it all out, then drop what you must, stack the brush where you can get to it easily. I too had to rent a chipper as mine would go into the area, but wouldn't come out without a large tow truck with lots of winch cable and blocks for redirects, and I couldn't get my tractor and bushhog into it. On mine, the wood stayed and the brush could be blown as chips. Maybe yours is a total removal of all debris? I pulled the rental vermeer 625 toy behind my 4 wheeler to the brush piles.
I had 3 days on it, sorta. 4 hrs underbrush, 9 hrs felling, bucking, and stacking wood, 6 hrs playing with the toy chipper with the insane autofeed 'feature'.
By your measurements you're looking at 1/4 acre, should be a cake walk unless you have a lot of big stuff comming down.
-Ralph