Check out RyanPyle's India Ride. Keep heading south into Kerala, then around the horn and up into Tamil Nadu. Rural, rural, rural. Decent roads in many places, brilliant mountains. Read God of All Things by Arundhati Roy. I have to say, culturally, India is much more of a feast than much of China. The stuff you see and experience will often be more interesting than the riding. But there is great riding to be had once you are out of the Maximum City (Bombay). Maximum City by Suketa Mehta is an other great book to read...

I know a brilliant temple at Thirukkurungudi in the mountains south of Tirunelveli near the southern tip of India that is managed by a motorcycle engineer from TVS Motors. The chairman of TVS finances the upkeep of 100+ temples in this manner. Thirukkurungudi would be great place to visit on a bike!

cheers
euphonius