Why do you want a USB mic? Are you going to record the voice over into your computer? I’d recommend doing it to tape. So i’d get an XLR mic and adapters if you need them so you can connect the mic to your camcorder.
If you are going to be on tour and expect to be limited in finding quite areas, a shotgun mic may be what you’re looking for since it is directional. Check bhphotovideo.com to look for ones that are in within your budget.
