In the field of navigation, there are now so many options and I think it's hard to make a recommendation. But sharing experiences is of course always possible.
I use a combination of an older, very robust Garmin 278 and a 10 inch Android tablet with which my inReach Mini2 is also connected. I get along very well with that. The advantage that I see in the combination of tablet and the inReach is that I can use the tablet for many other things besides navigation. Of course, the OB1 app also runs on it. With a tablet, app and the maps, you already have a good "all-round solution". Operation of the inReach with it via Garmin Explore is intuitive for me and works perfectly. This does not have to be so for everyone. Best to try it out or let someone show it to you. On the other hand, the Garmin Overlander/ Tread devices are more plug n play than a tablet I think.
There is not the only right solution and it depends very much on the personal preferences (smartphone or but rather a larger tablet or but rather a very robust GPS device or even a laptop or just so an all in one device). It is best if you take a look at the different possibilities to see what comes into question for you. It is also important to deal with the device BEFORE the trip, so that the navigation works well on the road. Maybe there are OB members in your area who can show you their setups live?
Please also take a look into the subforum
Overland Navigation. There you will also find many good suggestions and experiences of members on this topic.