This post has been on here for a few weeks, but I just saw it and want to share my thoughts.
Make it and keep it simple. He has several more years to complete world geography.
We use Visits to because of the variety of activities included. Also, the repetitive nature of slowing adding additional countries, rivers etc. helps reinforce the details and names.
My daughter enjoys studying the families from around the globe in the Material World and Hungry Planet books.
The additional living books recommended in Visits to have been excellent, but those are optional.
I definitely second the advice of others to relax and enjoy the process. I wish I had caught on to that earlier myself.