In my opinion the lenses you list are great full frame lenses. I have both the NEX-7 and the D700 and prefer using the MF lenses to their full potential on the D700. If you choose to use your MF lenses on the NEX-7 you will have no problems and will be able to use focus magnification and peaking. The 55 f3.5 or f2.8 Micro is my favorite Nikkor on the NEX-7.
If you do go for the NEX-7 the Sigma 19mm and 30mm are really good lenses and are as sharp as any of my Nikkors and are AF.