no time like the present to learn, you can pick up an aftermarket cooler for about 25 bucks which is pretty reasonable for the boost you can get.
Cooler master tx 4 has recently been released it should be a winner for you as it will fit more easily into a smaller case than the favorites of today cooler master hyper 212 / xigmatek Gia / any more expensive noctua coolers or most smaller closed loop water coolers.
the stock cooler should just be enough to take the cpu to 3Ghz
you can get a radeon hd 7770 to best match your rig . if you are going to buy a new pc in future years then you can overclock your processor to match the radeon hd 7850 graphic card requirements and then you can buy radeon hd 7850 .as if you are not going for a cpu upgrade don't buy a radeon hd 7850 ,just buy a 7770 it will be fine .overclocking a cpu decreases its lifespan (literally i mean it ).