Check the fitting of Honda Cd 100 rear shocks, as they can be altered to the size of Yamaha, i think.
For tires, in Karachi you have variety you can narrow it down to followings
1. Imported
2. Servis
3. Panther
4. Ghauri
For the light you can read the threads about HID or LED headlights fitting in bike. You have to set your own priorities. The original headlight is of no use if you have to travel alot in night. I am also using HID in my Honda Cd 70 model 2010. I can guide you in matter of HID Fitting.
1. First find an experienced electrician who have experience of fitting the HID in motor bikes, because fitting is not that difficult after fitting the repair is the main concern.
2. Find the headlight with the back of steel as the chrome with melt in ten minutes when headlight will start.
3. Find any good quality HID Kit. (Visit the car decoration shops in your area as they are dealing with the car electronics so they can help you in better way)
4. Buy a good battery atleast 7-9 AMP
5. Get the wiring sorted by the electrician.
The whole process of searching and collecting the items is very hectic, but it has good results in the end. Your budget should be around Rs.4K to Rs.5K for all the parts and labor cost.