If you want to use the side fan brackets, the C14s is the best cooler for the job. If you're want to make some sort of side panel window or do something that would remove the side fan bracket, you can fit up to 149mm tall cpu coolers. The Cryorig H7 or the H7 Quad Lumi would work well, but if you want the absolute best, the Scythe FUMA is perfect as it's a dual tower cooler that is 149mm tall exactly. I have a FUMA inside the Cerberus X and it fits, if just barely. You'll want good fans for bottom intake if you choose to drop the side fan bracket as your main intake fans are the bottom mounted fans. Do make sure you have good vrm heatsinks on your motherboard as tower coolers tend to not do a good job with vrm cooling as they mostly pass air above them, not at them.