The Asetek 645LT AIO is not great, I have just given up on the Dan with a 9700k at stock because of it. The one shipped from OC comes with a 1800 RPM Noctua fan (or at least mine did). You may want to buy an L9i and use the Noctua fan from it, which is a 2500 RPM fan, it helps things a bit.
It is significantly outperformed by the Noctua L12, or the big Shuriken 2, which are both small and air coolers, but neither will fit in the Dan. With hindsight is a poorly designed case, and extra 10mm in width would have opened up a decent range of CPU cooling options.
Sorry to be negative but messed about with this for 4 months, had a post in cases here, it is a bugger to fit too, you have to remove the pin fitment on both sides of the case to fit the radiator....
An extra 92mm fan in the base helps too, by about 5c on GPU, My AIO has the fan from the L9i on it, and then the fan is shipped with is in the base, being lower RPM.
Just moved the whole setup to a ghost which is night and day. That said, a 65w CPU should be ok.