I've spent the vast majority of my time in D3 with the Wizard and eventually worked my way to the end of Inferno but found the survivability to not be optimal to the point of relatively quick Paragon Leveling without having significantly good gear or perhaps I'm playing them poorly, which is possible.
I've found that Barbarians have the highest survivability of all the classes if done reasonably well and the highest level I've ever attained with a barbarian prior to starting my current (and only ever) HC Barbarian was 36. I've since worked my way to 60 (1) and have gotten what I believe to be relatively decent gear and I've worked my way through Act 1 Inferno with extremely little trouble using a Rend/Revenge build that works really well but I was hoping to get to Act 3 and farm MP0 using a Whirlwind build. Unfortunately I'm far from an expert on the Barbarian class. Below is the barbarian I'm currently using and sadly until I can get a bit more gold I don't know that I can upgrade that much further (I have a few million remaining). I know we have some exceptional barbarian players here in the HC community and I would greatly appreciate their input on what skills I should take (I know to change Furious Charge for something like Overpowered to increase Crit chance even more), how I should ideally play or any other helpful bits of advice they would wish to share, it would all be very much appreciated. My goal is to do MP0 Alk Runs to farm some equipment and paragon level relatively quickly and safely.