Probably not the H150i I don't believe it has standard mounting. You want an Asetek style pump which has the round locking ring to work with things like the NZXT G10/G12 bracket. (See their website for a list of compatible coolers)
An H150i is a bit extreme for a GPU as well, and you would still need a mounting bracket, probably more effective to buy one of EKs GPU cooling kits, even the aluminum ones. Once you start talking about 360mm coolers for a GPU, you probably do want to be looking at custom cooling anyway.
Arctic also sells decent AIO style cooling systems.
The DIY approach is similar, but the cold plate will only cool the GPU, so you still need fans/heatsinks for the VRMs and memory if overclocking. So decent case airflow...