Biab is a great tool for writing your own stuff.
You can save the files as separate audio files. Save to your desktop and then drag the files individually into GB or Logic 9. I like to build the bass part in Biab and also a drum track using real tracks. Maybe some fiddle back up. Then in GB the structure of my tune is done. The I record my guitar part and a vocal, maybe a harmony vocal. Then I am ready to mix! I know loops are great but they dictate what your music will sound like.
God Bless