There are a lot of different skimmers out there. Reef Octopus is a very popular brand that you might check out. The skimmer selection will depend on available space in your sump, budget, size of tank and the planned bio-load you are shooting for and any special features you are looking for (perhaps a float switch incorporated into the design to shut the skimmer down if the cup gets full).
I have used LifeReef, ReeFlo Orca and RLSS (which I believe is currently not producing new skimmers). The LifeReef is an old design and durable. It just works, but not "sexy" by today's standards. Virtually any pump with a 900+ gallon per hour volume will work on it. The one I have is still in use and is about 12 years old. Still skimming its heart out. I have changed the pump. The footprint is what is keeping me from using it in my new build. I will have a 125 (but it will have a total volume of about 160 gallons). So, I am going with a Nyos Quantum 160 for my new build. It is also a very popular skimmer, but mine is still in the box. So, I can't give any personal experience with it. I am hoping it works out ok. Here is a link to that skimmer - Nyos 160
I have used LifeReef, ReeFlo Orca and RLSS (which I believe is currently not producing new skimmers). The LifeReef is an old design and durable. It just works, but not "sexy" by today's standards. Virtually any pump with a 900+ gallon per hour volume will work on it. The one I have is still in use and is about 12 years old. Still skimming its heart out. I have changed the pump. The footprint is what is keeping me from using it in my new build. I will have a 125 (but it will have a total volume of about 160 gallons). So, I am going with a Nyos Quantum 160 for my new build. It is also a very popular skimmer, but mine is still in the box. So, I can't give any personal experience with it. I am hoping it works out ok. Here is a link to that skimmer - Nyos 160