I suppose Sadanand are considered the best . They may still be available although I heard "Sadanand" has become to old to make them anymore There is a thread about them somewhere deep in this forum with a web link
I think Sadanand tablas are considered the best because Zakir plays them. Rest assured that the quality of drum they make for Zakir WON'T be the quality they make for you. Online ordering of a tabla is risky. You might end up with something you don't want. With the high shipping cost, there is no real recourse. I would suggest finding a tabla shop near you and actually testing out the drum before you buy.