Now that I know more about what you want to do, it does sound like BiaB will get you a long way much faster than RB, learn RB when you need to.
You'll already know the song structures and chords, finding a style is much faster in BiaB. Then maybe you can add your audio there too if it's only a few fills. Could be you don't need RB at all!

I do not work here, but the benefits are still awesome
Make your sound your own!