Ouch.
I will get roasted, but between the two I would pick the Cyberpower model. Consider that the power supply is probably trash, and the motherboard is likely a lower end chipset. I notice it doesn't say whether the 16GB of RAM are a single stick or not. It is highly likely that it is, and should consider buying a matched set. The case on it has more airflow than the HP. By my experience everything inside this unit should be "standard" parts with industry standard connectors for such as the front panel wires from the case.
Their support could be anywhere on the map. They used to be FAMOUS for poor back end service and support.
The HP Omen line is...well...The case airflow is almost non existent. It doesn't show a back view but often HP will use some wonky off standard power supply that is (like above) also junk, but sometimes due to the size format and/or connectors cannot be replaced with a standard unit like the one above. It will almost assuredly be one stick of RAM as well. The case and motherboard may or may not be industry standard for the connectors meaning that you couldn't change the case or move the components over to a standard without adapters. MIND YOU- I do not know all of these factors to be true concerning this specific model, just some educated guesses based on what is and has been common out of them.
Their support will be your typical "down a list" type thing.
I know you are asking about a Prebuilt computer, and can understand why behind it. It is hard to recommend the off the store shelf items. If you go boutique pricing can be prohibitive. I wouldn't personally suggest you get either of them, however I feel like I described my own opinion on why the Cyberpower would be my choice of those two if there was simply no other option.