Between the 2, I'd go leupold. Vortex isn't junk by any means, but you can bet when you buy a leupold it will be crystal clear through its full power range and eye relief is still easilly attained on high power settings. As the Vortex that's not exactly true for all of the scopes they offer.
If your going Vortex do allot of research to be sure the scope can be used for its full intended purpose. You'll probably save a few bucks over the leupold if you choose the right one the first time.
As for Leupold, pick the one that suits your needs and start shopping, no need to research it because it WILL work.