You can use the E2160 cooler but you'll want to keep an eye on the temps to make sure they stay under control.
The stock cooler heatsink for the E2160 isn't as large as the cooler that shipped with the E6750.
E7200 Wolfdale performance is just a bit behind the E6750 at stock speeds.
If you were thinking about overclocking then the E7200 would edge in front of the E6750.
Of course you'd need a better cooler then the stock Intel cooler.