This is what I use.
Polyphaser coax lightning protectors with a flange mount to bolt them on to copper ground rod clamp for each of my antennas. I also have 3 ground rods 8 ft. long driven down and all are tied together with 4 gauge solid copper ground wire. This is a more expensive setup costing more than your antenna, but it is rock solid and I can only hope it will work as advertised.
If not, I have a separate insurance policy that covers all my radio gear and connected equipment with full replacement value for both my home and mobile station so I completely covered either way.
If your interested, here is a link for these products.
http://www.dxengineering.com/search...4294953334&SortBy=Default&SortOrder=Ascending
We use this on both of our local repeater antennas on 2 meters & 440 mhz & we have had direct hits to the antennas that were destroyed yet we have never had any issues with the gear in the repeater building.That is pretty good results I think & better than any other systems I have ever seen used.Antennas we can't save but repeaters have been safe so far.Nothing is 100% lightning Proof but these have been worth the money for sure.
SIX-SHOOTER