If you do end up with a 60 of any type, and plan to use a power cable, you might want to make one of these, the design of which I just thought up this afternoon.
The holder is by RAM, "RAM Mount Plastic Garmin GPSMAP 60 and Astro Series Mount Cradle", you can see it through the link below.
http://www.gpscity.ca/item-ram-mount-garmin-gpsmap-60-and-astro-series-mount-cradle/ramholga12.htm
I use a Garmin GPSMap 60CSx and the only thing I don't like about it is the fact that the power cable has nothing holding it in. It falls out often.
This is what the back of the gps looks like, in the RAM mount:
This is not helped by the pFranc power cable
http://www.pfranc.com/ I made up, but I like the setup so I gave a little thought to the idea of keeping the cable in and came up with this:
This is just a flat piece of plexiglass which I cut up and is now sandwiched between the RAM diamond mount and the RAM gps holder, and which keeps the power cable from coming out unless I remove the gps from the RAM mount.
That should be the end of that problem, I hope.