A Canon A80 may fit the bill for you. The image quality is very good, has manual controls and long battery life on AA batteries. I really like mine and think that it is a terrific value.

The G5 is a good camera, but many people think that the G3 is better. I think that the benefits of the G series over the A80 are mostly the external flash possibilities. If you have an external flash for your N80, and don't have a Canon compatable flash, then you may want to look at the Nikon equivalents/approximations to G series. If you don't, then maybe the extra size of the G series will not be warranted (obviously, this is a preference thing )

In anycase, I think that you are looking at good cameras, and will be happy with what you get. Have fun!