I'd really think twice about putting up lightening rods.. In my observation, they are much more trouble and expense than they are worth...
Do Lightning Rods Attract Lightning?
We had them installed. Lots of ugly rods - you see homes in TV with them.. unsightly. We took a lightning strike. It ignored the rods and came in the bathroom and hit our wall tile, that was a metallic gold color, and travelled across the room to the plumbing.
All the rods did was cause roof leaks.