If you are staying mostly on the PanAm Hwy, most any hiking gps will do you fine for all your needs. I traveled some of CA & SA, and where I've gone, paper maps lack enough detail to navigate with any confidence. I found OpenSourceMaps (free) loaded on a rugged Garmin device with a larger screen worked best for me. There are other gps map sets that are good/necessary, look on this HU site for a list. I plan my day on a small laptop using Open Source Maps loaded on Basecamp. I transfer my route or track to my gps and I have a decent navigational tool for the day. The paper map gives me the big picture and the GPS gives me the details. I use a reconditioned Garmin Montana, about half price of new, and it works very well for my CA/SA travel destinations. I think it will meet your criteria. I tend to ride more dirt roads in to smaller towns and villages, vs staying on the more traveled blacktop. Hence, my choice. It depends on where you plan to ride. More remote mountain village areas will not be easy to navigate using paper maps.

There is also a smart phone app that works without wifi or phone access, if you have a smart phone. A lot of overlanders like the app - maps.me maybe. Read through this web site. There is a lot of good information here and you should be able to make a decision based on what kinds of roads you are going to ride.