I also vote going with two camera's. I shot an event and had both camera's on tripods. What I did was moved between the two tripods to do my raw video shooting. Obviously, while you're at one of the tripods, you do your zooms and pans and closeups with that one. When you move away from that tripod, you zoom out a little bit and leave that as a static shot, but zoomed out so you aren't missing too much action.
Doing it this way keeps a great dynamic going on with the final mixed down video. For one, the static shot is never always the left or the right camera. For two, the zooms and pans are never from the same right or left angle.
This takes work and you can get kinda tired by the end of a show because you're running back and forth between cameras every 5 to 10 minutes. However, the results are EXTREMELY rewarding. Obviously, it's probably best if you have two camera operators, but the problem there is that both operators need to be kinda synched with their filming techniques on how they capture the video, how they do pans, and zooms. If their technique is very different, then that can be obvious in the final mix too.
I personally wouldn't worry about whether or not the camera you buy has audio input. I'd get a recorder and run your audio completely off camera so that you don't have to worry about hooking up any mics or whatever into your camera (with cords to trip over and extra crap connected to the camera). The reason is that since you're gonna be mixing two separate video sources anyway, the audio will need to be stripped off from the video anyway, so you're gonna need to sync up the audio with both video's regardless.
So I just run my audio separate into my audio rig, which is higher quality audio that way anyway.
BTW, this is VERY fun and very rewarding to do. Also, in order to do this, you'll need to get your hands on Vegas or some other high quality video editing software.