It's not really about being "top of the line" so much as appropriate for what you want to shoot. The two macro lenses I would choose from are the Nikkor 60mm micro or the Nikkor 105mm micro. The 60 mm will double as a portrait lens as well as a macro lens, but won't get quite as up close as the 105mm. However, with the 105mm, you're more or less stuck just doing macro. There is no real impact on which housing you use, Ike/Subal/Nexus, as well as a number of other housings, except for the availability of a proper port for the lens. As far as quality of glass, if you're concerned about that, I doubt very much that you'd be unhappy with either, but if I were to select one as being better in that regard, I would give the edge to the 105mm. But don't choose the lens based on anything other than what you wish to accomplish with the lens.