I'm not sure about books for sight reading and slap/pop. But here are some ideas for learning to create interesting lines...
You might want to check out "Building Walking Basslines' by Ed Friedland -- a lot of people on TB like it. I have (and like) some of his other books too -- for example one on blues, and also a book of reggae lines. He's prolific and his books are consistently good, IMO.
http://www.amazon.com/Building-Walki.../dp/0793542049 http://www.amazon.com/Blues-Bass-Ess...ref=pd_sim_b_2 http://www.amazon.com/Reggae-Bass-Bu...4361902&sr=1-7
And just I got 'Bass Blueprints' by Dominik Hauser. I've gone through several beginning and intermediate books, and found this one extremely useful. I came to this book at the level where I could get by in a jam situation by hearing a root note, finding it on the neck, and then cycling through the notes of a major or minor triad or 7 chord. Adequate but boring. This book helped me push past that to the next level showing how to play extensions, passing notes, and more unusual chord types besides triads and 7 chords. (And not just showing how, but also explaining what those things are and why I'd want to use them!) After reading this book, I'm able play more interesting lines, and to understand any type of chord symbol I'd find in a fakebook. I really liked this one and want to give it some credit because I don't see it discussed much here on TB.
http://www.amazon.com/Bass-Blueprint...4361955&sr=1-4
Looking for a good intermediate book 
