Raijintek Triton radiator placement in NZXT Phantom 820

So I have a Raijintek Triton and will be mounting it in my Phantom 820. The 820 has a 200mm fan at the top that I would have to drop to install the radiator up top. I would think having the radiator up top would allow for the heat to go straight out of the machine. If I install it low I can keep the fan but all the radiator heat would be spread through the system. Any suggestions? IS it worth keeping the extra fan or should I ditch it and top mount my radiator?