For the CPU a Cooler Master Hyper 212+
will fit in that case and out perform the stock cooler. You will need some thermal compound for it though, $7 more for some Tuniq TX-2
If you're worried about inside the case, not sure what to tell you. The NZXT Apollo only has 3 places to put fans, and comes with 2 pre-installed.
If you set up the CPU cooler so that it pushes air toward the rear exhaust that will help. You'll also have a fan over the GPU to help cool that down. Just need to pick up another 120mm for the front intake. Rosewill 120mm Blue LED
for $8, and you get a blue glow coming out the front of your case.
Please read through the thread thoroughly before responding.
Nobody wants to read a wall of text, formatting is your friend.
i5 3570k | 8GB G.Skill 1600MHz | R9 290 | SeaSonic 750X