I would go with a tape based HDV camera. I have a Sony HVR-A1U and love it. I payed less for it than my Canon GL1. It uses the .m2t format which most nle’s can handle. Most HDV cameras can also down convert to standard definition DV as well if needed. Vegas pro 8 can handle the hard drive camera files that are AVCHD files but most other nle’s need to have them converted before they can work with them. The reason I say tape based is it’s an inexpensive way to store video but even more important to me is if you record long sections of video without stopping the recording, you have to import the whole thing to your hard drive even if you only want a small part of the video. I believe Vegas sees those cameras as a hard drive and cannot capture just a section of a long clip.
Hope this helps. Danny Hays