Rick,
I spent about 6 months looking for the right affordable chipper. I assume your looking for a new one since buying used long distance is really iffy. What you want from what you describe and mention budget wise, I would suggest you look at the Wallenstein choppers, chipper/shredders.
http://www.embmfg.com/forestry/chippers/BXT
Their videos were the ONLY ones which showed self-feeding branches with limbs. If you notice all the others show their 3 or 4" branches as neatly trimmed sticks. Which brings up another point. Are you planing on just doing just 3 or 4" branches? If you plan on doing limbs smaller than an inch or two than you
should consider a chipper/shredder, which is what I have, since for the most part anything bigger than 3" I use for
firewood or let it rot in place. The model I have has a Honda engine and the shredder will grab things out of your hand-it's wicked!
I have the BXMT 3204 and have no complaints. Cost = $4000. Even at that cost you shouldn't expect any sort of high end production rate. But those on Permies who are familiar with my writing,know I'm in to slowness
.