Personally, I would not purchase the Canon SX-20, SX-30, or the Nikon P-100 at all. They are either ISO limited or have received poor professional and user reviews. My choice would be the Panasonic FZ-35 or FZ-40.
Now I know that Panasonic cameras are expensive in India, due to a distribution problem in India. So, as a result you should consider a DSLR camera which would be more useful to you in the long term future.
If I remember correctly, there is good distribution of Canon, Sony, and Nikon cameras in India. Therefore your more realistic consideration may indeed be a Sony A-230 or an A-290, followed by a Canon 1000D/XS model. I would stay away from the Nikon D-3000, and the new D-3100 will probably be too expensive.