Sir an aftermarket Head Unit like Alpine or Pioneer will look much cooler and will also sound much better, better radio reception, a future proof investment, will look good with a white/black contrast on dash panel.
A used Alpine from new Corolla/City will cost you 5K Rs, no USB but IPOD compatible with a separate cable, a new Pioneer 5250SD for around 12-13K Rs with Ipod, Iphone, USB and SD card reader and OEL display.
However, it is a personal choice not necessary if you do not want to spend right now.
For Bulbs visit Plaza, go straight in the line of Tibet plaza, after Japan Plaza across the street, there is a shop called AUTO LINE, another one in the same line called MASTER BULBS.
Bosh premium and Narva long life are also good, OSRAM night breakers would be expensive, high end product, maybe north of 2,000 Rs, but worth it.