I agree 100% with WIK.
Flat copper strap is the best to use for your ground conductor, Sometimes available at reasonable cost from upscale roofers who use it for roof flashing......
A good ground "system" has a number of ground rods, Rule of thumb is twice the distance apart as the depth..........
For good info on proper grounding, check the tech notes on the Polyphaser site, and also this one:
http://members.cox.net/pc-usa/station/ground0.htm