HD for sure. Can't tell you what brand/model off hand but definitely HD.
If you're thinking of doing some shooting I'd strongly recommend the Sony V1-U and the Cannon VH1-A. These are both relatively inexpensive and very high quality picture wise.
Both use hard drive and tape so you can choose how you're going to capture images (hard drive is better overall but tape is more convenient since you don't need to reload every half hour).
You'll also need a good editing system and I'd suggest going with Final Cut, which is very user friendly.
Hope this helps!

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