[AZTLANLC]

We have installed couple aluminum fences and have found out that Jerrit and Delgard are some of the top choices, I like jerrit a little bit better, installation is easy if you have an auger.
Some contractor I have talked to like to install them using the dry method which we might try next time, other said to use the quick set pre-mix concrete, some companies recommend to dig the hole about 3' depth and put down couple inches of clear gravel before pouring concrete.
The method we use is to make a 3' hole with a 6" auger bit, put down 2-3" stone fill hole about 1/3, cut a 20" lenght 4" drainage pipe and insert it with the post inside fill the inside of the pipe the final concrete should be about 6" below the bottom railing, set the section and next to the other post.
We use 6" auger bit but the final hole is more like 9-10" depending on soil.
We also use the pipe because most manufactures recommend to make the hole wider at the bottom in order for froze not to push the concrete up, but most of the times is harder to accomplish this using an auger and with the soil conditions around my area.

a 100 feet fence is about a day job with 4 guys and auger (note that we have a bobcat mt52 which is similar to a dingo which I think is the perfect machine for this job.

We buy our fences at fencesforless.com you can call them and set up a contractor account and pay less, they have lot's of fences in stock and prices are the best I have found, shipping is free to a commercial address or $100 to residential.