In the world of coolers, bigger does translate to better. All 120mm AIO are quite bad at cooling as they are the smallest. Stepping up to 140mm radiator they are better but not much better performance for their price. Only the 240mm, 280mm and 360mm radiator are good for their high price tag. I would say any 280mm/360mm are great for you, just look for one that has robust warranty. I know Corsair and CoolerMaster has 5 years warranty while Deep Cool for example has 2 years only. EKWB CLC Predator is now discontinued while they are preparing to launch the successor MLC. Swiftech is also another good brand.