Its a serviceable case but, to my eyes, not the best choice in that price range. CM Site says:
Front = 140mm x2 (pre-Installed) 120/140mm x1 (optional)
Rear = 140mm x1 (pre-Installed)
Top = 120/140mm x2 (optional)
The GPU puts out 193 watts when gaming, add 17% if using MSI Afterburner, say 226 watts. The CPU, overclocked figure 125 and 30 watts for the MoBo and 40 for everything else, say 420 watts. With 140mm, 1200rpm fans you are good for 75 - 100 watts per fan or about 4 - 6 fans. You can do 6. Intake fans will have their air flow reduced by the inlet air filers which can be as high as 30-33% if they significantly dirty. So you want at least about 50% more intakes then exhausts
As delivers, with (3) fans, you're fine ...tho if overclocking (adds about 75 watts) I'd want more
(2) Intakes w/ 33% restriction gives you a "fan equivalent" of 1.33 fans
(1) Exhaust w/ 0% restriction gives you a "fan equivalent" of 1.00 fans
So even under worse case "I haven't cleaned my air filters in months" situation, you have positive case pressure.
Now I see ya have (3) added fans in ya parts list ... what's the plan ?
(3) Intakes in front w/ 33% restriction gives you a "fan equivalent" of 2.00fans
(3) Exhaust on rear and top w/ 0% restriction gives you a "fan equivalent" of 3.00 fans
With more air going out than in, where is that make up air going to come from ? What are the biggest openings with least air resistance ? Looking at the pics, the case has a H U G E open rear grille and your only concern might be "well i guess i will have to clean some dust out cause I have negative case pressure. That is the least of your concerns. Look at the picture again.
Your 750 watts PSU is exhausting all its hot exhaust out the rear of the case. Your 226 watt GFX card is exhausting a significant portion of it's air out of the rear of the case. By creating a negative pressure situation in the case, and with the "path of least resistance" being the rear case grilles, the source of the make up air into the case will be that rear case grille.
So if ya going to add a fan, make it a front intake fan. The 4 fans come sup just 20 watts short of meeting the rule of thumb described above. if you want more, by all means ass the two fans on top. But, you will have to forget 8th grade earth science and learn a little bit about college level thermodynamics. Hot air does not rise in the face of a ceiling fan in the room and if you want to stop the hot exhaust from PSU and GFX card from being sucked into the case, you will need positive case pressure and that will require putting those fans in blowing down.
As for which fans to pick, Phantels has the best fans on the market at present... replacing the fans on a Noctua cooler drops CPU temps by 6C at the same rpm
http://www.overclockersclub.com/reviews/phenteks_f140/3.htm
Also come on top here:
http://www.silentpcreview.com/article1345-page7.html
Ya might want to consider a Phanteks case which have been very stronly reviewed.
the Phanteks P400S is designed for quiet operation and this one has a gorgeous Temperd Glass side panel for $10 less. Cooling wise, much the same w/ main difference is that the rear fan is 120mm mount and only 2 fans included
https://www.newegg.com/Product/Product.aspx?Item=N82E16811854053
The Enthoo Pro is also $69 - 89 and its fan capabilities are but it comes with a 200mm in front:
https://www.newegg.com/Product/Product.aspx?Item=N82E16811854018
https://www.newegg.com/Product/Product.aspx?Item=N82E16811854003
Front: 2 x 140mm fan
Top: 3 x 140mm fan
Rear: 1 x 140mm fan
Bottom: 1 x 140mm fan
Tweaktown rates the Pro 98, 99, 100, 98, 99 compared with the CM MCP5's 95.98, 98, 96, 99
If ya can swing the extra $30 ... the Enthoo Luxe is my favorite here... with fan storage on top being able to be stored "in the attic". Overall cooling is phenomenal and you can actually fit (2) 140mm on the bottom
Front: 2 x 120mm / 140mm fan (1 x 200mm included)
Top: 3 x 120mm / 140mm fan (1 x 140mm fan included)
Rear: 1 x 120mm / 140mm fan (1 x 140mm fan included)
Bottom: 2 x 120mm / 1 x 140mm fan
HDD: 2 x 120mm fan
The case is also capable of fitting HUGE CPU Coolers, tho the MC5 is no slouch here either.