It seems people are always in search of a new devotional book. I might suggest a very old one. The Psalms have functioned not only as song book but as devotional book for the church throughout the ages. Since we devote few Psalms to memory anymore (save the 23rd), it would be a good task simply to use the Psalms in daily devotion and prayer enough to become familiar with them. More than a passing familiarity gives us a rich resource not only to read but to carry with us in hearts and memories.
Crossways has come out with a Book of Psalms that might just fill the bill if you are looking for a devotional text.