I second the 60CSx/76CSx recommendation. I have the 60CSx and it does everything you're looking for and more. The electronics are identical (other than a slightly larger microSD card that comes with the 76CSx), and the 76CSx floats. The primary difference is the placement of the buttons (top on the 76, bottom on the 60), so try holding each if possible to see which placement you prefer. The other difference is that the 60CSx has an external antenna "bump" on top, the 76CSx has internal antenna. Both can use NiMH batteries and can be set to tell the unit that's what you're using so the battery life indicator is accurate.

If you use either at all for car navigator you WILL want to get City Navigator North America (another $100 or so), the base maps that come with the unit are virtually unusable for driving anywhere off major highways.