A minor but important point. Make sure that the available products support your application speeds during quiescent conditions. If inside the building, you may only need a single stage lightning protector with just one type of switching element, e.g. silicon avalanche diodes. If the cabling is outside the building, your equipment may be more vulnerable to a direct strike. If after surveying the market, you still cannot find an appropriate device, do not give up.
Many vendors offer services to design and manufacture any type of protection device.
119, No. 2 Feb. 1992, pp. 65, No. 63, March 1977, p. 466. McGraw Hill Encyclopedia of Science and Technology, Vol. Georgiadis, N., et.