When you're running something at close to 50% overclock, your temps will DEFINITELY jump.
I'm not surprised that it got to 70C, especially since its on a stock heatsink.
That nirvana is not too shabby, with 4 heatpipes. Google it, and take a look at its design. If you can't get the exact heatsink, just look for another with a similar design (note: 120mm fans are good, there are 92mm versions of such heatsinks out there somewhere... not so good). There are tons of them out there. Some don't come with their own fan (but you can buy your own and install it), so take note.
Also, since these heatsinks use a larger fan, you can the fans slower, and still blow the same amount (or more) of air, so they'll be quieter. They tend to be much much bigger than the stock intel heatsink fan combo, so less air is needed to cool the CPU. All in all, you should get: a cooler CPU & less noisy.
About your question, your m/b is a full sized, standard ATX board. It should fit without a problem.