I would go by the recommended tank size on bulk reef supply website. I have little to no experience with hob skimmers but I agree that Reef Octopus is a good option when it comes to skimmers generally speaking.
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Thanks for your wisdom as alwaysReef Octopus Classic 90 Hang-on-Back Protein Skimmer
Unique skimmer design with cylindrical body which uses the siphon to feed water to the skimmer. This reduces the load on the pump while increasing the air intake. Rated for aquariums up to 100 gallons Powered by Aquatrance 1000 Pinwheel Pump Design reduces turbulence Capable of surface skimming...www.bulkreefsupply.com
This is what I have and would work for your tank too. BRS is out of stock though