Typical residential grade panels from Hardie or Nichiha are 5/16 inch thick, while the commercial grade panels are 7/16"
We are using the 5/16" residential panels rom Nichiha. It's a great product and its made in Georgia. In addition, NichiPanel is available in 12' widths, which reduces the number of seams and the potential for water leakage. Here's a link http://www.nichiha.com/home
The residential panels weigh about 2.2 lbs per square foot, so the larger panels can weigh 75 - 80 lbs. The panels go up quickly, but it takes a three man crew to support and fasten these heavy sheets.
We originally planned to use Tamlyn aluminum reveals between panels (see the How To section) but the logistics (and cost) of using the reveals was just too much.
We decided to use simple galvanized Z channel between panels and use thin battens to create shadow lines.
Here's a couple of pics. And... The trees are turning green!