Welcome to the forum! You can most certainly get the 70# version and dial it down easily and efficiently; especially with the Fury cam. If you are going to spend the money, I'd get what you want, and turn it down until you're comfortable.
Now on the other hand, to play devil's advocate, 60# is more than enough for any big game in the US. I shoot a 70# Onza atm, but my next bow will be a 60# offering, probably a Cougar with the Nitro 2 cams or an Alien with the Hybrix. I can get the same speeds out of them with a lighter arrow and only lose a little bit of my kinetic energy. Just food for thought.
Whatever you buy, know that with Martin you'll enjoy a great bow, at a great price with outstanding customer service and wonderful brothers in arms here!
Good luck and great shooting!