If you have the rear drive cage installed, it does limit your PSU choices somewhat. You have about 220mm of space between the drive cage and the rear of the case. This doesn't leave enough clearance for you to use a 200mm PSU (AX1500i, AX1600i, HX1200i) as well as the rear drive cage mount. So if you are planning to use one of the big PSUs, you'll need to take that into consideration.
With a 180mm PSU (HX1000, RM1000x), you'll have room enough for the second cage and your PSU without any problem.