AIOs are more prone to failure and you pay more for the same level of cooling performance compared to air coolers. Unless you are restricted by a small case or RAM clearance, or only really care about aesthetics, air is usually the better choice. Your case is wide enough that it should fit any high end air cooler, so unless you plan on buying RAM with huge heatspreaders or are going all out on RGB lighting and plan on getting RGB RAM sticks too, air is still probably a better choice. Since this is a locked 8700, you don't need a really big air cooler either. Something like a Cryorig H7, which won't cause RAM clearance issues would be sufficient and offer similar or better cooling performance to a 120mm AIO.