It depends on the processor your using and your case, as previously stated P55 runs much cooler than X58, and is a cheaper platform. What case are you going to be using? or no case at all ? whats your budget? Also will you be running P55, or X58? Now that said there is no way you can make the argument of a stock cooler being able to compete with an after market fan. But if your using the X58 platform like a i7 920 or a 940 going to 3.2 isn't really a stretch on a stock cooler. If your using the P55 platform an i7 860 or 870 you can squeeze by with the stock cooler. P55's overclock about the same as X58 processors and run cooler to boot, but some don't get HT.
You can get a decent aftermarket cooler for about $20 - $50 dollars, but as is the case with almost all computer parts you get what you pay for. X58 is more powerful and has the advantage of tri channel memory. With P55 They run cooler than their 1366 counter parts also the amount of memory needed is less, and the motherboards and processors are cheaper. Your case will also play a huge role in the temps of your processor, cases the the HAF
932 and
922 push a lot of air through the case, and as such have lower ambient, and GPU and CPU temps.
20 dollar coolers
1156 (P55)
Cooler Master ( decent cooler, but the mounting brackets are kind cheap)
Masscool
50 dollar coolers
1156 (P55)
ARCTIC COOLING
Thermaltake Silent (just kinda meh, but better than the stock cooler)
ZEROtherm (pretty good and very quiet cooler also fits 1366 (x58))
1366 (x58)
Thermaltake CLP0533
60+ dollar coolers
1156 (p55)
Prolimatech Megahalems ( no fans, but you can get a set of fans for 20-30 dollars, also fits 1366)
1366 (x58)
CORSAIR Cooling Hydro Series CWCH50-1 (great preformer, can upgrade, by putting a bigger better fan on it, also fits 1156)
Noctua(quiet and gives good temps)
Noctua NH-D14 (amazing temps, whisper quiet, and fairly simple to install, and has the option for a third fan, but is a little on the heavy side, also fits 1156)
Thermaltake SpinQ (quiet, adjustable fan, installing isn't hard, but not "easy" also can block the ram slots on some motherboards, also fits 1156)
ZALMAN CNPS9900ALED (quiet gives great temps and is easy to install and fits 1156 also)
ZALMAN CNPS10X Extreme (quiet, easy to install and has an adjustable fan, also fits 1156)
These are just a few recommendations, and suggestions and is by n on means your "only" options. But they are good strong choices.
Now all that said said and done, if you could give us some more information on what your setup will be. Like what platform (P55 or X58) your motherboard, and processor, even ram, and what case you will be using. We can help you out a lot more. There's just too many unknown factors to make a good recommendation for you. But should you choose to go with the stock cooler, getting to 3.2 with a stock cooler though not impossible you can expect be running at 70+ C at load which is kinda hot, it may not be your best option, the cooler your CPU is running the better. Please post more info on your future rig so we can help you out.