In JPEG FINE mode you will get only about 25 images on a 64-meg card, and only about 6 images in RAW mode. You'll need to look into much higher capacity than 64-megs, or you will be changing cards constantly.
You DO get a 30-day trial copy of NC3 with a D100.
PS7 has the amazing Healing Brush, and enough stuff in the interface to take a 6-month college course. With Photoshop, you can do almost anything that can be done to an image or graphic of any sort. With Elements®, you are a bit confined, since it is designed for working with images, and has much less deep control over color channel stuff. But, Elements® is the way to go, if you are simply modifying your cool photographs, since it automates many functions that are difficult to learn in Photoshop proper.
Enjoy your D100, and POST FREQUENTLY with your experiences.