I assume you are talking about walking bass lines in the jazz styles.
There are between 4 and 10 variations for each chord depending on how common the chord qualities are.
The variations are randomized so even after 10 choruses you might get some repeated lines while some other ones are missing.
A simple way to transcribe these is to export a tune to midi and open it in a notation software like Sibelius.
Tempo won't affect the choice in bass lines but choosing different styles that are optimized for different tempos will yield different lines (slow swing vs. up tempo swing for example)

As a bass player myself though, I'd recommend that you rather transcribe Ron Carter, Ray Brown...

Massimo.