I would book the balcony cabin you can get at the best price. Oasis is an extremely stable ship, so I would not worry about motion, but do try to avoid being all the way forward if possible (some motion up there)
Soundproofing is generally very good, but I always take earplugs with me every place I go anyway.
I am the editor, but I also speculate, ask questions and play devil's advocate. I reserve the right to change my mind.