I would pick scp 3008 because it is easier to survive there.
3008 and backrooms have similar features, being infinite and filled with entites. but entering the 3008 ikea form anything other than the main door will lead to the non anomalous interior of scp 3008 you are not alone, there are probably hundreds of people inside scp 3008 that have built5 a fortress using ikea tools.
Scp 3008-2 (entities) are harmless and randomly wander during "day" but react violently if attacked. during night, they will start syaing and mumblin "Leave the store, its closing"
After some time, they wil start attacking any human they see, so that is why they need to build shelter. They are not immortal, they are easy to kill
So choose 3008, idk about you guys tho