I understand your concern fully. Your graphics card (MSI GTX560 Ti Hawk) dumps at least half of its heat inside the case. This heat must be extracted out of the case as efficiently as possible. IMHO, the best escape route for this heat is through the top case exhaust fan. See red arrows in pic 1 below.
I suggest keeping the stock configuration of your Rosewill Challenger, with a few important modification:-
As you are using stock Intel HSF, this means it is the downward blowing type. This means that after hot air is exhausted by the hawk into the case and is being pulled upward, the hot air might be sucked into the CPU HSF. Obviously this re-circulation gives negative impact to your CPU. To prevent this and, at the same time, to enhance the cooling to your CPU, I suggest you to install a 120mm intake fan to the upper fan opening of the side panel. Additionally, use an air duct/air guard (see pic 2 ) to 'hover over' your stock Intel HSF in order to focus directly fresh air to the HSF (see the green arrows in pic 1). This is an essential step. With this fan and air duct deployed, hot air from CPU will escape through the top and rear exhaust fans (orange arrows).
Last, install a 120mm intake fan to the lower opening of the side panel to increase fresh air supply to the card.
I got a little antsy and started messing with it. I ended up running the exhaust out of the top because I realized that GPU fans are intake fans, not exhaust fans. I had no idea that the heatsink and fan setup blew air INTO the card, which completely nulled all of my ideas about it blowing air in the wrong direction.
@Windfire, I did do something just a little differently, and that is, I took my side fans and installed them above and below my GPU, both blowing upwards. But I'm just trying to be creative, as my side fans never helped my temperatures (CPU or GPU) a whole lot. However, they're not very good fans, so this could be one of the reasons.
In any case, the new layout of the fans dropped my temps from 84C to 76C under load.
Thank you EVERYONE for the help.