Just to answer the original question, you're not really going to find a book that will have walking bass lines written out for a lot of standards. Mostly because the idea is that, if you are playing in a quartet, that there will be two choruses of a (for example) 32 bar tune played (the melody in and the melody out) and at least one chorus of solo for the lead instrument, the chordal instrument and maybe even the bass. So that's 5 times through the form, or 160 bars of quarter notes. For even 50 standards you'd be looking at something like the Encyclopedia Brittanica.
There are a few books that will have a few standards with 1 to 3 choruses of a written walking line, mostly with the idea that you'll just keep repeating the written line until you start hearing the changes enough so that you venture outside what's written with your own line.
But it's not really that walking lines are "all about theory", they only came to be taught that way when formal academic jazz courses of study came about. My suggestion would be to start (if you aren't already) listening to the way the "language" sounds, not to try to grab notes or phrases, but just to hear how different players move the harmony forward. You will find, as most of us did, someone whose playing speaks to you on a very personal level and you'll want to start tearing their lines apart to try to understand why they made the note choices they did.
If you're going to be playing the standard repertoire, yes you'll need to have some grounding in how functional harmony works, just like you'll need reading skills. But if you want to play this on any musical level at all, you'll need to understand that EVERYONE in the group should be improvising. Because ultimately this music is a conversation that each musician participates in and contributes to.
I need only bass walking lines, don't really look to learn all the jazz theory.
