After much research, this is the system I'm upgrading to. This system will mostly be used for mapping old logging roads not on the topos. (paper or digital). Garmin 60csx, don't need the 76csx as this is not a marine application and the 60 can hold lots of info, just put your streets on one chip, your topos on another, or if you work in different areas, have a chip for each. It's cheaper and more flexible.
As the 60csx will be mounted inside the vehicle at the bottom of a stack of electronic gear (laptop,scanner,2 way radio, sat. radio) I will be using an external ant. (Gillson-cheaper and better than OEM). This will be mounted in a custom made rack as I have been unable to find a rack to accomodate all this gear. Yes I checked out Ram-Mount thoroughly.
Because these roads (well, they were roads 65 years ago) are quite rough, I will be going with a solid-state laptop, model TBA. The prices on these laptops are expected to drop signifigantly in the coming months and because I can't start mapping until the snow goes, (April-May?) I'm holding off on this part.
The maps are TOPO 50 which are already loaded in the current laptop.(Toshba Satellite) This covers S.E. BC, Abbotsford to Alberta, Blue River to the 49th. Every day I thank my lucky stars I'm Canadian. Best police force in the world, best hockey teams in the world, back bacon, maple syrup etc.
Onto this I will be adding Ozi Explorer 3D. No point putting it on this 'puter as I'm upgrading anyway. A system like this will do everything you need/want and more.
Hope this gives you some ideas.