Also I would recommend a good book on yoga. I am a big fan of B.K.S.Iyengar work and 2 particular books by him could be really good for you:
"Yoga: The Path To Holistic Health"
"Back Care Basics: A Doctor's Gentle Yoga Program for Back and Neck Pain Relief"
http://b-k-s-iyengar.1.searchbook.net/ or try Amazon or book stores.
A like your approach to take it slow. Also good teacher is essential. A general rule is: you feel good and energized after yoga session. If you feel wasted - try to take it slower or change class.
I found some info on 5 tibetians at:
If this is what you were asking about - it is very soft dynamic yoga cycle.