Check out the following places:
Jail road and surrounding area (i.e. the road which connects Guromander and Jail road) there are several shops.
Waterpump (F.B. Area) the shops around PSO petrol pump. I mostly buy from Superway autos just beside the pump. The rates are so-so but he is an honest guy as he tells you if it is a Japanese or a Chinese part.
For the "patti", it may be just dropped due to hit at some speed breaker. But radiator is hold by the screws and bolt so don't worry too much about this. However, check out the silencer welding shops, sometimes, they do have a solution.
Hope it helps. BTW, getting a second opinion is better. Check your car at RZ Autos (on the road between Disco Bakery and Bhayani Heights). The guy name is Zulfiqar. Get an estimate from him as well. He will save you from buying parts etc.