I think you all missed the part where he said he wants to upgrade his cooling.
Instead of good advice on that everyone tells him what a piece of shit he has. smh
OT@OP
Yes your cpu isn't the best for WoW and other cpu demanding games, that being said, if you can play at 1080p with decent settings, then you might want to wait as memory prices are fin ridiculous atm.
On to your cooling.
Get a 120mm fan for the rear, grab 2x120mm (or 140mm) for the front. Since you have some type of filtration on the front you want to set it up for positive air, that will keep the dust out (more air being forced in than coming out).
Heres a video that explains it, yes its old, but it gets the point across.
Decent fan manufacturers are Noctua (recommended), BeQuiet! and Corsair, there are a few more but thats a starting point and is also a matter of opinion.
Start there, this will get the heat ouit of the case and provide fresh air, after that if the cpu is still a little warm re-seat the hsf with some good thermal paste, again this is a matter of opinion, I use
Thermal Grizzly However, you can get anything from Arctic Silver 5 to Noctua
Good luck and let us know how you proceed.