Is it possible to load a non-aviation GPS with airspace markings?

My Garmin Pilot III just bought the farm, and I'm looking for a replacement.
I recently took a car trip woth my brother and his MIO C310x GPS. Pretty
cool device. Even found a restaurant in Washington DC for us.

I'd like to pick up one of these types of units, but I'd like to be able to
use it in my plane. I figure I can load the airports as waypoints, and
'goto' that waypoint. I used to do that with an old hiking GPS I used.

What I would like are the airspace rings depicted around Boston, Providence,
Manchester, Bradley, and the little class D airports around too.

Can this be done? Anyone have a screenshot?