All three of those cameras a fine. Not a bad one in the lot. If you can find any of them for under $1,000 go for it! You won't be sorry using any of them.

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The aim of an argument or discussion should not be victory, but progress.
Joseph Joubert, essayist (1754-1824)

I had the same budget as you, and I too am a high school filmmaker. I ended up getting the Panasonic AG-DVC20p, which I am very happy with. It is only $1,139 from ?url?www.Buydig.com?/url? and I was satisfied with their service. I chose free shipping (7-9 days), and recieved it in three. However, I had to reorder twice, as they had trouble processing my credit card order. I'm not sure whether this was their fault, or the banks, as I had just changed my pin code. I am very satisfied with the ergonomics of the camera, and it has manually adjustable focus, white balance, exposure, and various other features I am still getting acquainted with, as I just recently got it. It comes with two batteries, and just about everything you would need to do some run and gun shooting with it. I highly recommend it, especially since you are used to the DVX100, and in my opinion Panasonic's have a unique image quality that lends them to filmmaking. Unless, of course, you are looking for something HD, in which cause I would recommend the Canon HV20 for your budget.

"We all have the potential to be great. It is our inability to do so that makes us miserable." C.S.Lewis