Hi, never owned an iPad and I'm struggling to choose between a few models. With a movers coupon, I can get the Air 2 for $449 or I can get a 64gb or 32gb Air 1 for $444 and and $404 respectively. Air 2 has a great processor and more memory but I'm worried that 16gb won't be enough for future apps and releases of iOS. A 32 or 64gb Air 1 lots of workable space and a slightly better battery but less memory. Any thoughts?