Walt has been providing his book for free at his online website which is [last I checked anyways] in its 8th edition since first being published in 1980. I bought hard copies of both the 7th and 8th editions. He added over 100 page between these two alone!
The only scientific argument I’ve encountered over the years had to do with the fracture of the hydroplate heating the oceans to a boiling cauldron. However the skeptical ‘scientific’ argument failed to regard the effect of ripping a seam in the earth’s atmosphere that would circumnavigate the globe and mitigate the heat gain with a heat loss and an instance ice age encircling the poles primarily.
You two would also probably enjoy my other creation science links on my FR account links page. Lastly, Walt too was somewhat of a former atheist/agnostic even though he was raised as a Methodist. Another excellent source for defending the faith is Lee Strobel. Have you heard or better yet listened to his books on disc:
The Case for Christ
The Case for Faith
The Case for Creation