Hi!
Unfortunately Pharaoh’s Boat has gone out of print. If you can locate an inexpensive used copy, snatch it up however it you can’t, don’t feel obligated to purchase it. You can find resources at the library that you can substitute.
I didn’t see a mention of your children’s ages however we do suggest that if your oldest are 1st or 2nd grade, take a look at a sample of Exodus: A Commentary for Children and Numbers: A Commentary for Children. You may want to read the commentaries for your own instruction and then read aloud only snippets or simply narrate what you read to your children. Some families chose to omit the commentaries all together for the earlier years and that is fine. Simply read the assigned Bible passages.
While Genesis through Deuteronomy look a bit light, the Bible is the main history book for the guide. My older two children and I are finishing up our final week and I can’t believe how much we learned! I’ve been reading the Bible most of my life and I am still walking away regularly saying, “I didn’t know that,” or, “Oh! that makes sense now.”
I’d encourage you to become familiar with the other history guides. There is much depth and variety of books scheduled in the guides.