Corsair Crystal 460X questions before upgrading

I'm looking to make a new build very soon, probably after Ryzen launch and I want the Crystal 460X to be my new case. My idea was to build an entire RGB-based PC, by buying 6X HD120 fans and replacing the SP120 with the case and also installing them on my cpu cooler radiator (Corsair H110i v2).

First easy question: can I use HD120 fans on the radiator?

Lets say I can. I read around that when mounted to the top side of this case, the second fan over the RAM sticks can get in the way with the slots. That would prevent me from using either some types of memory sticks or the second HD fan. Is there really such a little space between the top side and the motherboard ATX mounting slot?

The SP120 controller that is pre-installed on the 460X can be used by HD120 as well or are they different?