Hello TekRice,
There is a pre-fabricated hardline kit BP-TEKIT-3090EVFTW with this water block.
https://www.bitspower.com/titanseries/expansion_kits/
But it is only compatible with your current Titan X 1.2.
It depends on your requirement of temperature. If you want the temperature lower, adding one more radiator and upgrade the existing pump is a good choice.
If you want to add one more radiator, you have to change the current loop.