Outdoor X4 Magazine just published a simple review of the various GPS devices that can be used for off-road navigation.  While my personal preference is to use Backcountry Navigator on a Samsung tablet in my vehicle (for both topo mapping and APRS) and a handheld Garmin for locating and deploying the caches, there are many other devices out there that will get the job done.  All of them have a learning curve, and it's best to practice ahead of an event, or at a Meet & Greet with the Land Ops leaders.  Check out the article here...http://www.landops.wildapricot.org:80/resources/Documents/Outdoor%20X4%20GPS%20Article%20R.pdf