Since Aperture only processes the B in camera setting, maybe you should start your Post Processing with a program that processes all of the in camera settings. Nikon View NX 2 and Nikon Capture NX 2 come to mind. You can then directly transfer the images to Aperture once you properly configure the Nikon program.
One of the big issue with trying to emulate the in camera settings in a 3rd party program is that the values used to set a level in the camera do not match the values used in other programs for those same settings. Nikon might use 1-10 but Aperture could use a setting like 0-9 or 0-255 for the same setting.
In general terms, the Vivid profile adds significant contrast and color saturation, coupled with increased sharpness. I would try altering those, coupled with a slightly increased black point. Personally, I wouldn't worry about matching the Nikon profile - just get something that you like.
Have you tried the Presets on the Adjustment tab in Aperture? Settings like "Punch" or "Intensify" under the "Color" submenu on the Presets button? You could start there and see if you like the results and adjust to your taste. If you're particularly fond of the Vivid settings, perhaps you want to set the image quality on the camera to capture both raw and JPEG at the same time with JPEG set to vivid. Then you can adjust the raw file in Aperture to mimic the vivid JPEG out of the camera and then save those settings as a preset.
Very simply that is why I use Capture NX2 or even View NX occasionally for color corrections, WB, exposure adjustments etc. and only use 3rd party software for things like cloning, adding text (signature) etc. I have found that starting from what is almost like a blank canvas is just too much work.
Marc There are always two people in every picture: the photographer and the viewer.-Ansel Adams