I can’t personally attest to every individual cooler thermalright makes, because they have literally hundreds of options. However, on the whole they are quite reputable in the industry at making high “bang for your buck” products. Both of these product lines are incredibly similar, and I would expect similar results from both. The one difference I note, looking at the product pages, is the ss 110 has slightly higher fan RPM and moves more air per minute than the pa 90se. More air moving through the cooler may theoretically lead to better cooling performance, depending on your use case. From a thermodynamics standpoint, the extra heart pipe could make a minor difference in extreme cases. It’s all about total surface area. But I think that would be splitting hairs. You indicated you’re a beginner and don’t plan on pushing your rig too hard, so I personally wouldn’t get too caught up on which cooler to use.
The 212 works great for me. My current rig runs a 13600k, and I game at 1440p and aim for 60+ fps. The same with rigs I’ve built for others, no temp issues. In one instance my brother-in-law had overheating with a different cooler that was fixed by installing the 212 I recommended. The only limiting factor for you is space. I mostly build atx because I like the extra room. No idea how it would fit in your build.
If you want more in depth info, gamers Nexus does great breakdowns of the peerless assassin and silver soul lines. I didn’t find videos specifically for the 90se and 110, however, the videos for other coolers in the same lines will give you a general idea of performance to help make your decision. Good luck!
Yes, I preloaded my steam wallet yesterday so I could skip the card step. I happened to check the store page 2 minutes early and it was live so I sent it.