Not to confuse the issue, however, you have a multitude of tools at your disposal both free and paid.
In my experience, cheaper ( or free ) software does not normally play well with higher end applications ( WebEx). Your best bet is to stick to a suite of tools ( ie Adobe Captivate for video and Adobe Audition for audio) or stay with higher end tools like Screenflow or Camtasia.
Regarding hosting platforms, I would steer clear of Vimeo as they are somewhat late to the HTML5 game, and I have had one too many customers experience difficulties viewing content. Some alternatives are Brightcove ( my personal favortie), YouTube, Screencast.com, Blip.tv, or Viddler. These are all pretty intuitive platforms and vary from free to expensive.
There are a ton of factors that go into making a decision, but hopefully this post helped rather than hurt.