The cooling potential of the TJ08-E is superb due to the huge front intake fan and system configuration. The air pressure is excellent inside the case and in an air cooled rig is basically all you need, there is no need to put extra fans in the back. In fact I found the AP181 to be more than enough so replaced it with a Phobya G Silent 180mm 700rpm with a resistor to reduce the noise levels (and air flow/pressure) still using the switch for high and low speeds. This still allows me to use a modest GPU passively and keeps temps well within limits. If you only need 1 small radiator then it's fine, larger radiators will cause some difficulties especially if you want a very quiet PC.
My main concern is silence, I know I need fans and they will always produce some sound but my computer is spooky quiet.
I would use either a 120mm rad with 120mm fan behind it (pull config) n the back of the case or a rad being blown through by the front fan, if I needed only 1 rad. I like the idea that some people have used which is a 200mm rad at the front, not sure if that would be quiet enough for me though.