I would rather get a aio for the cpu and mount it as top exhaust.
This way it dumps the cpu heat outside the case and will lower case temps a lot, usually enough (~30C) so the card doesnt have to speed the fans up to vacuum speed.
My 1080@2ghz doesnt even go past 83C under full (game) load,
but doesnt crank up the fans as much.
Also more universal (future cpu upgrade) and usually cheaper and easier to do than swapping gpu cooler, not even talking about the fact that most lc/aio for gpus arent designed for that use, but modified cpu coolers.
A decent block isnt enough, you need reservoir/pump/rad/hoses/connectors/coolant,
not gonna happen cheap, even going with value stuff.
If you really want lc, go with ek predator or better...