Let me first admit to being totally ignorant about professional filming despite the fact I have, whether by dumb luck or divine providence or both, managed to get decent preliminary work done on the project below. Using a Sony TRV-140 handycam. I'm here because despite my luck, even I can see the shortcomings of my current camera and it wouldn't be fit for commercialization of the final product.
I will try to give as complete information below as possible without taxing your patience with too much text.
I'd like advise on buying a camera that will provide a quality job for what I want to do. I'm producing a DVD based curriculum in which the primary language of communication is American Sign Language (ASL). Thus the videos need to be sharp and clear for this visual language to be perceived with clarity.
Because a fair amount of the work will cover history, some filming will include elements in which I will employ chroma keying using such software as Ultra 2 and virtual sets from other software such as Elite Video. I expect to make limited use of special effects where appropriate to illustrating o enhancing instruction content using VisionLab Studio. So quality video will surely help here. Because I don't have a studio, I do as much filming as possible using natural light, which for me usually means waiting for a cloud day or morning hours before the sun has reached the backyard patio. I've managed thusfar to produce shadowless video. So a camera that can produce quality video under these circumstances is very helpful.
I'm not rich and a lot of what I have came from buying things one at a time over a period of time and via mercy selling where some companies gave me truly deep discounts for some software. Still, what research I was able to do,it seems the two best bets for my use are:
1. Canon XH A1 Black 1/3" 3CCD 2.8" LCD 20X Optical Zoom High Definition Professional Camcorder
2. Sony HVR-HD1000U MiniDV 1080i High Definition Camcorder with 10x Optical Zoom
But it's what I learn from this forum that will dictate my final decision which may be one or neither of these. Your advice is urgently desired and hugely appreciated.

