What's your budget?
I use a garmin gpsmap 60CSx, works pretty well. Not ideal, but gets me where I want to go. Using PC, you can plan routes and mark waypoints + routes, download them to the unit. Can be had on eBay for ~300. I loaded bluechart data instead of road data. PM for details
If you don't mind greyscale, I do have a Standard Horizon CP150 with a C-MAP chart. Chart is from the 90's, but can be updated. Good enough. See
MANUAL (9mb slow download) for details or google CP150. Just collecting dust, will let go with wide area C-map chip (erie, st. clair and Huron) for $200 & help mount.
PM me for more details, can set up demo. Have small boat now, and it will be a chore to make it fit anywhere else I would be using it myself.