Have a look in my build log (in my sig), I have a water-cooling setup in a HAF-X.
If your talking CLC/All-In-One water-coolers, everything but the dual 140mm rad units will fit fine in the HAF-X. The thing can fit a triple rad just fine, a dual rad is no issue.
Also, if your friend isn't willing to build their own computer, don't give them custom water-cooling. Because no doubt something will eventually go wrong with the rig, and having water inside the computer just adds another layer of complexity to what is already confusing to an unknowing user.