If you already have a custom loop setup just finding the right GPU block for your card would likely be your best bet...
take a look at the sticky on the top of the forum for specific vendors.
If you do not, then you will need to look into setting up a custom loop and cooling your graphics card, and whatever else you decide you want to liquid cool (CPU, MB, etc.)
do you have a budget that you are willing to work with?
If you don't have a loop already set up then it will not likely be very cost effective unless you are interested in watercooling in general or want to set up a loop for more than just the graphics card.
I was kinda hoping they'd be a "sealed" range for gpu cooling like there is for the cpu.
I'm hoping you understand the price/performance of these solutions vs. actual watercooling solutions as part of this equation. Yes, a few exist, but my real question is...why do you want to spend that much money on a mediocre LCS? What temps are you seeing that make you believe that an LCS GPU cooler is worth the money, but not the temps you'd get from an actual water loop? I only pose these questions to help raise the understanding of what you can expect from a cooling solution in a best case scenario...if you have poor case airflow, you are still likely to suffer from heat issues, although not as often with a form of LCS or watercooling.