I think your odds are good.
How well you can OC haswell is primarily determined by your luck in getting a good chip.
4.0-4.2 is very reasonable. past that.....
A cm hyper212 is not far from the top of the line noctua or phanteks.
I think you may be leaving 0.2 on the table without a top end cooler.
I would take what you can get with a conservative oc and not worry about more.
Over time, you might revisit your oc. As thermal paste breaks in, the cooling gets better and you might gain that 0.2 back later.