where to get posters??

hi!!

i'm looking to customize my room more with bigger posters, but i'm not quite sure where to start about getting prints online. idk if i want to support places like amazon; i normally buy them from local chain stores, and they're pretty big.

same topic, different side-- i have an elevated cathedral ceiling, how can i maximize the space up there and prevent it from looking boring and minimal? it's weird because of how high up it is, it's hard to think of things to put all the way up there.

toodaloo