Need front fan if have side panel fan?

[Slam]

Just got a Fractal Design R3. I'm running cpu/memory/gpu at stock speeds and am happy with temps. However, I'm about to install a 2nd GTX 460 and will overclock.

My question is, do I need a front case fan if I have a side panel fan for intake and one rear plus one top fan for exhaust?

The drives are 2x Western Digital blue and an SSD. Is the front case fan basically just cooling these drives?

CPU is SBridge 2600k, GPUs are GTX460s in SLI.

 

[Slam]

So basically a slow quiet fan at front for hdds and on side panel for GFX cards. Both don't need to push much air as they're right by the components they'll cool.

Then fans on top and rear to shift more air so that hot air exhausted as fast as possible.