@smartkid808 With fans on only a single side of the radiator, I'd want the airflow being pushed through the radiator. You can actually go with fans on both sides of the radiator if you have the mounting space for everything, which we know you don't in this case. Bottom or top only really matters depending on the airflow through the rest of the case. If you want to bring outside air in through the radiator, then on top. If you're pulling air in from within the case, then on bottom, and is the typical airflow setup where air comes in through the front of the case and exhausted out the top/rear.
I miss the combined radiator and water reservoir from years ago. It sat outside the pc case because it was so big, but because it was so big you also didn't need any fans on it. I saw a couple systems built with it that water cooled the GPU and CPU with the thing.