Resource can i use a heavy rope for hanging?

[Haibane-renmei-reki]

I finally found a store where i live that sells ropes in meters instead of kilos or bulk, but it only sells 2 brands, the first is super cheap but not very strong, the second one is heavy and a lot more costy, i would go for the first one only if i get thin, but i would prefer the second brand for now, but i heard people advising against heavy ropes here, so I.D.K, thoughts?
sadly, i do not know the names of said brands, and i doubt the seller himself can name them

am going for full suspension hanging, BTW

 

[Haibane-renmei-reki]

@Worndown can you help me?
Thank you