There aren't that many units and you might not get what you request.
x502, x508, x522 are pier-facing rooms so you will hear a lot of noise from the pier especially during parades and WoC. If you are unlucky there might be rehearsals at night after the park closes. If you want a good view of the pier request high floor.
x514 faces the Redwood Challenge Creek and is generally pretty quiet even during the day. You will still hear some WoC noise at night however.
x507 are the only 1BR that face the pools so those will be the quietest rooms you can get.