Hi Samik,
Recently we were discussing about accessories for i10 sports model with Shilendra. I suggested him the accessories and prices also , you can view that thread.
Do not buy anything from the dealer as Pankaj suggested they will take very high prices from you, buy everything from car accessories shops outside.
Coming to your requirements -
No need to go for any type of flooring, just buy good quality foot mats which will cost you around Rs 750 to Rs 800. They are more than enough to protect the original car floor carpet.
Do not know exact prices of mud flaps but should cost around Rs.400 to 500.
As i suggested Ryder covers to Shilendra, i would suggest you also to contact Ryder people,they must be having a distributor in kolkata , get quotes for pu seat covers and steering wheel covers from them, i have bought leather covers for all my four cars here in kolkata. I got them from Ryder Mumbai years back. Other brands cost you Rs 5,500 and same quality Ryder cover would cost Rs 4,000. Contact them for exact quotes or ask their dealer number of Kolkata. I have explained in details about the seat covers in Shilendra's thread.
You can go for Ambi-pur car perfume costing around Rs.150 or others which are imported ones but bit expensive around Rs.550
Other members have given the explaination for the under coating.
You can go for sunfilms of 2 companies , one garware which would be around Rs.1250 and Llumar which would cost you around Rs.2200
You have to tell me more about the music system you need , whether you like loud music , or you need high bass effect etc. After your explaination for the music system i can give you all the details, so let me know about it.