Get a good idea of the average size of what you are going to be chipping and buy accordingly. You can't go wrong with DR Chipper, excellent performance and warranty. Also in response to RickCorey's comment about waiting a few years, call it hugelculture and plant on it, instead pile the brush up in a short row about 3 feet high and wide, cover it with a layer of humus or leaves, cover that with a layer of good dirt and plant right away. Plant on the tops and sides. It will be virtually self-watering and self-feeding and will not take up a large amount of space and will produce copious amounts of food.
