Installing the XD7 in the front is pretty straightforward ... but it leaves a space in the front that I found a little odd. The XD7 mounts on the inside of the fan tray, which would work if the fan tray could be reversed. Instead, you have a chunk of space - where the fans would go - in front of the distro. You can put a 4th fan at the top, with the XD7 mounted all the way to the bottom. However, if you do this, you'll see (in the inset) that you don't have very much clearance for the fittings on the one side of the radiator. So if you want to use the XD7 and have a radiator mounted on the side, then you'll want to have the XD7 centered vertically to give that clearance.
An XR5 360 will fit just fine in the side with the XD7 in front. However, you won't be able to manage push/pull on the fans. The top could be an XR5 420mm or an XR5/XR7 360.