In all honesty,
No.
Your CPU will not significantly "bottleneck" your computer if all your doing with it is playing games.
Do not listen to these people and their quad cores! (Yes quad cores help in many ways, but isn't the most economical route to having fast games)
The performance difference between having. An i7-990X Extreme edition ($1000) and a i3-2100 ($124) is 30%. So you will see a ~30% fps increase in gaming performance, for an 806% increase in price. While you are not making the jump between these components, it illustrates my point.
Since you are upgrading your cpu anyway I just flat wouldn't worry about it.
In my books you overclock your components for two reasons:
A. You enjoy a challenge so eeking every bit of performance out of your components.
B. You are suffering from insufficient performance and don't have the money to upgrade.
While looking at your... temps... is important, in the cpu's case you generally never approach the thermal design limits of your processor unless you have a really poor cpu cooler.
You should look out more for erratic behavior of your computer. I could cool my computer to -100 F and there is still a point where the increased frequency will destabilize my computer, cooling it better definitely helps you reach higher overclocking potential, and it is also very bad for your cpu to run at 90C, but chances are you will suffer from instability before temperature damage.
As for Quad vs. Dual.
In games, in most cases you will not see a large difference in performance going from Dual to Quad. In every day tasks you will definitly see an increase in your multi-tasking. But always go for a Dual core with the individual cores being fast, before you go for a quad core with slow individual cores.
BUT XRAIN!!?!?!?!!! A FASTER PROCESSOR WILL PROCESS MY GAMES FASTER!!!
Yes you are right, but there are other things that will increase your performance MORE for the same cost. (This of course changes depending if you mostly play games or do photoshop/CAD. But I'm assuming you mostly want to play games)
Lets look at the tasks that each component has in your average game.
CPU
- Positioning Computation
- Tells the GPU how everything should look
- The millions of minor tasks making everything work together
GPU
- Renders a Frame according to instructions from the CPU
The CPU's task is indeed complex, but on the whole isn't very strenuous. While the GPU's task is simple (relatively) but there's a crap ton of it to do, the cpu can only issue instructions as fast as the GPU can render the scenes.
So in the case of games, unless you have a very high end GPU, you can get away just fine with a somewhat underpowered CPU with a stronger GPU. Note however, you will probably suffer in all other areas of your computing other than games, but if you find it's performance sufficient out of games, then all you really need to do is upgrade your gpu and you should be just fine.