I am not familiar with that device but if it stores .img files get one from here http://wiki.openstreetmap.org/wiki/OSM_Map_On_Garmin/Download
I have used .kmzs on my Garmin Oregon 450 which are fine for small areas but I also have a large .img of western Europe which I am very pleased with. I Downloaded it primarily for the device but it works on Basecamp from a memory stick. It is convenient to have the same map view able on both platforms in my experience. A limited range of Garmins will disply display .KMZ a file see https://help.openstreetmap.org/questions/27269/is-there-a-simple-way-to-create-a-garmin-custom-map-kmz-type-from-osm-data