If you keep lines clean enough when drawing, you could even get away with adjusting the levels in Photoshop and get a nice outline. A god thing is to draw on a clean white paper, you never know what use you might end giving to the original drawing even if you plan to outline it.
I always sucked at inking, so that’s what I do, and I prefer to color directly over the pencils anyway. I like the original trace to stay visible, but that’s not what you where asking.
If you really want a clean digital inking, I recommend Manga Studio. It has some tools specificaly made for this, to fix movement caused by the pulse and to give different width to the line while drawing.
As I said, I always sucked at inking, but I made this the first time I touched Manga Studio 4 Debut.
I got it free with Tial Pay:
http://manga.smithmicro.com/specialoffer/
Vectors work, but it can get boring (at least for me).
Have you tried with real ink the traditional way? Maybe you’d do a lot better than me. I did tried! -.-