For CPU+GPU, the 360 is a much better option as it allows you to run a lower delta when choosing between a single 240 or 360. It also means that if you decide to add another GPU in the future, you might be just fine using the same, single RX360 or only need to add another 1x120 or 1x140 at most instead of a 200mm, 240 or other rad.
However, you could get by on a single RX240 if you weren't going to overclock and used some good fans.