I am not up to date on Nikon goods. However, you might consider the following: A reversing ring for your 50mm. A 2x extender for your 50mm giving you a 100mm 2.8 which shoukd work nicely stooped down 2-3 stops and focus quite closely, 200mm f4 with 1.4x and 2x extenders and get rid of both zooms. Sounds like a nice kit to me. A 28mm or 35mm wideangle would fill things out nicely.