Hi Pierre,
I'm not familiar with wikindx so can't speak to its strengths and weaknesses, especially for your particular needs. Did you consider Zotero or Mendeley? They are mature products that do everything you describe, and they're free (up to a point). If you did consider them, I'd be interested to hear what wikindx does differently. EndNote is also out there, but I'd steer clear of it unless you have a large EndNote user base already.

Josh