For anything more than light-duty, occassional use, I would recommend the Bearcat.

Here is a link that might be useful: Bearcat Chippers

My husband likes this one. They specialize for the rental market, right? Scarey to pay so much $$ for something that might not work. DR has the return policy, but we're not impressed.

Anyone else?

Tree Tools - www.treetools.com - sells arborist gear and they include that Bearcat. It's not really what a pro would use but it is much more sound than the home depot toys.

Bearcat is just out of the toy range. The small chute might be the limitation.

You can rent a big one for a day if you have the right rental yard nearby.

There are no rental yards here that rent chippers of any sort. Believe it or not. We figured that they must break down too much. We checked them all, even the industrial ones.

My vote is for the BCS. We had owned their 2 wheel tractor for 8 years and were absolutely sold on the quality of their product so we got one of their chippers 2 years ago and just Love it!
But whatever you do do not buy a Sears Craftsman. They are absolutely worthless!
Good Luck
Glenda