If you do chose to go this route and use an A-Mount adapter than I would highly recommend that you look into old Minolta lenses. If you are going to be shooting manual focus anyway you'll save a significant amount of money by buying Minolta glass. Why pay for new lenses with autofocus if you can't use the auto focus? Besides, old Minolta lenses are very well built and optically great.
Havoc315 could probably offer a lot of advice if you have any questions about the old Minolta lenses.
I do love some old Minolta glass... but..
I haven't done it, but I'm not enthusiastic about using the adapters on NEX cameras.
For A-mount to NEX, Sony makes 2 adapters. One of which will turn A-mount lenses into manual lenses -- LAE1/3 adapter -- About $199.
But I don't get buying a technologically advanced camera.... then adding another $200... for the joy of attaching old cheap lenses and using them as manual focus. It would be like paying $2,500 for a top of the line computer.. then stripping out the CPU and guts..... and turning it into a type writer.
They also make an adapter -- LAE2/4 -- About $375--- That fully supports auto focus on NEX cameras. But it also adds a fair amount of bulk to the NEX. NEX cameras are mirrorless ---- The LAE2/4 has a mirror --- it overrides the NEX AF system, and basically turns the camera into a dSLT.
It can make sense if you already own a bunch of A-mount lenses that you wanted to use. But wouldn't make sense to spend $375... and turn your sleek mirrorless camera into a bulky mirrored camera, just so you can add A-mount lenses. Plus, use of the adapter hurts the camera's high ISO performance.
Spend $400 on the NEX... another $375 on an adapter to turn it into an A-mount dSLT -- For $775, you could have gotten the Sony A77, the premium top of the line APS-C Sony dSLT.
Instead of buying the adapter and then the lenses -- it would be cheaper to just by an A-mount camera in the first place, OR simply buy the native NEX lenses. Yes, the lenses are more expensive -- but still cheaper than buying the lens + adapter. (You'd have to buy several lenses before you are "saving".... and the lenses won't work as well as native lenses designed for the NEX. They will also add bulk, and hurt ISO performance).