I just downloaded (and purchased) Videobox from tastyapps.com yesterday. It does exactly what you're looking for. Costs $15. The demo is fully functional, but only lasts five days, so play with it as much as possible to make an informed decision. I paid for it within 30 minutes of downloading it.
However, I did a quick test of the quality of the .mov file created with Videobox vs. simply downloading the .flv (as "raw") using Videobox and then converting it to .mov with VisualHub. The VisualHub file looked better to me.
So I'm going to use both apps, even though Videobox will do it all. With a Mac Pro (see my sig for specs), the conversion doesn't take long so it's no big deal for me.
James