Originally Posted by hzac
Im getting the NZXT phantom. I wont really have room for a 360. only a 240 as far as i know
You're going to be going with a CPU loop only for now, but if you decide to add a GPU then you'll likely need to add an external radiator to the mix if you don't mod or get a new case. If you don't think you'll be willing to mod or put up with an external rad for future upgrades, then just go with one of the sealed units.
If you do want the option of GPU or motherboard cooling in the future, then definitely go for the rs240 (or rx240 if it will fit).
The main value of a custom loop is that the parts will last you a long while and it gives you far more options than a sealed unit ever will. It's also quieter and cools far more efficiently the higher you overclock.