Hahah that link is for a 300R ink cartridge. But if you open in a new tab it works. ANYWAYS. No, you don't need side pannel fans. Heck, you dont need fans at all.. But if you don't want your components to die in a year its probably a good idea. With the 300R there is "two 120mm/140mm top fan mount locations, two side panel 120/140mm fan mount locations, and two front panel 120/140mm fan mount locations. Now for a complete setup for fans this would be Ideal: two high cf/m 140mm fans for intake and then for exhaust I would do the two upper fans as quiter 120mm fans with a lower cf/m and then run two side panel fans off a fan splitter. The side panel fans would be the same as the top exhaust fans. Then the PSU would be fan side down and...