what types of yoga are best for working on the low

Sat Nam,

IAlthough all the yoga styles have exercises for the lower back, I would recomend Kundalini Yoga

I am sending you these links with specific exercises for the lower spine.

http://s3cr3ty0stg2.wpengine.com/Yoga_4_spine.html

http://s3cr3ty0stg2.wpengine.com/newsletter/12-2008/exercises_maintain_flexible_spine.html

Blessings