Ok, so I see two issues here:
1) Buying/using quality stuff
but also..
2) Trying to prevent the LEDs being ruined or burdened, by ANY form of unexpected power surge, or whatever can happen, when having my project powered by a 9V/12V wall wart, plugged into the 10A fused sockets in my apartment. After all, I just want to try avoid having my installed LEDs being damaged in any way, at all costs so to speak, by being extra careful if there is a way to be extra careful in how the circuitry is designed.
I really want to try add some stuff to the circuitry if that can help against obvious or not so obvious power surges, but ofc, I am not that knowledgeable to even know if or even how power surges could possibly affect my LED project if I were to have that stuff plugged and maybe running all day.
I could be wrong, but I do not expect heat to be an issue with my led setup, as these are well, tiny LED's. I guess I can add to that comment, saying that the LEDs will be inside a closed model with no ventilation, with the model placed in room temperature, and afaik the LEDs would work with maybe 10mA or such. I am only at the start of collecting the LEDs and I haven't even started testing/playing around with the LEDs yet. My newly acquired variable power supply has shipped though, so it should show up in a week or two and so I can start playing with this stuff before committing to designing or installing the LEDs for the project I am working on.
Regarding branded LEDs, feel free to add some link where I might get to buy those from some website. I have so far been using eBay to get the cheap stuff, but I am willing to try get the possibly more reliable stuff elsewhere.
Off topic: Speaking of LEDs, today I had to return a pack of 5x 7W LED spots used for my ceiling lamp to the store (I still had the receipt), as all five had either died or stopped working properly. The pack of 5 LED spots cost $35. I have NO idea why they failed, and neither does the seller. The spots previously installed in a new ceiling lamp for 4x spot lighting (the fifth one was used as a replacement as some point when the installed spots started to fail). My three LED spots in the kitchen (different design) seems to be working still.