I'm interested in getting a not so terribly expensive Nikon kit. I don't need metering so non-AI is fine with me. I'm interested in these focal lengths: 28mm f2.0, 50mm f2.0, 105mm f2.5. Maybe a 20mm f3.5 or 20mm f4.0 too. I'm undecided between some AI and non-AI variants. I believe some Nikkors have CRC. Should I go with any updated optics for these intended focal lengths?