the biggest road block to MP10 is resistance and then some sort of life replenish.
the problem with using a shield is u potentially loose 900 life on hit and 3% life steal as well as substantial attack speed (which in effect makes LOH and LS much better.
so u have a few options when thinking about whirlwind:
using a shield u get much more survivabilty, but your LOH will be largely nerfed due to slow attack speed, low DPS
using a belt, main hand, off hand with life steal at 9% coupled with 200k+dps
a mix of both LS and LOH with a fast offhand for maximum coefficient from tornadoes coupled with high dps
very high LOH on ur weapons sockets ammy's rings and low dps due to nerfed coefficient from tornado's
there ya go... btw u need very high resistance as well do too monsters attack being buffed.
regardless of what route u go, i think that using a shield is a good idea when doing uber bosses.
Hey, I am sword and board and have significantly worse stats than yours (48k dps, 50k life, 800 resists, 25% block, almost 11k armor) and I found that doing MP5 for the keys worked well for me. I would get five stacks NV then go hunting for the warden, it took a little less than an hour per run. Elite packs usually took between 2-3 minutes to kill depending on affixes (bloated malachors with exta life being an outlier). I can survive MP10 but I see no point in doing so, it is SLOW. Its like using a toothpick to dig a whole through a mountain. With your stats, you should have no issues with MP6-8 as your regular farming.
All that being said, I highly recommend you try out the PTR for yourself and see how the decrease in defensive stats affects your build and playstyle and how that will ultimately affect your farming. I found that I didn't need ignore pain anymore and replaced it with battle rage since it lasts 120 seconds now. I still use warcry impunity because I am still in the mindset that I really need resists, but that might change as I get more used to the new patch. Also, if you want to level a new char, try it on MP10! I think thats how diablo 3 was meant to be played on normal mode anyways.
Farming uber bosses at the same MP level where you farm the keys (or maybe 1 max 2 levels above if you can survive it with your "normal" gear) will be faster than hurting your DPS a lot so you can do MP10 if you share the machines with a group. Being able to do 4 uber portals for each 1 machine you farm makes you spend almost 1/2 your time actually doing ubers (and the rest of the time you farm keys, solo or group doesn't matter as long as you're being fast).