Angie,
I think Michele's suggestion is a good one. The D70s has been out long enough that there are plenty of used ones on the market. The following link is an example I found on ebay after a 30 second search. There are hundreds of them to choose from. If you are not ebay proficient I would check your local photo shop.
http://cgi.ebay.com/Nikon-D70s-6-1-M...QQcmdZViewItem
This camer: DSLR, is a much better choice than any point and shoot variety. The learning curve would be not much different than it would be for the Casio, or any other new camera. Also, the ability to shoot many pictures in rapid succession is not really something that will benefit you in this work, but if it appeals to you the D70 is up to that task.
I have shot the D70 for about 4 years now and think it is all the camera a portrait artist would ever need. There are newer, more featured camera now on the market, but we have to remember that we are not creating photographs as an end result, but as a point of departure.
I have also use my D70 with the with the standard kit lens and find that it works pretty well in most circumstances. Lens envy is an easy thing to fall into. I wish I had one of the good fast lenses, but fact is they cost as much or more than my camera. I say get as good a lens as you can afford. If a kit lens is all you can afford then strap it on and go out with the confidence that you can get the job done. It's more about the mind behind the camera than the equipment.
I have shot enough good photographs with this set up to be confident that if I do my job well enough, the camera and lens are up to the task.