Here are my questions:
1. How long does it take to fix all?
If your engine does not require work and is completely good then the installation won't take more then a day or two depending on the availability of the stuff that must go in.
2. What kind of parts do you want to use, manufacture? (Sanden, Denso, other)
Sanden and Denso are widely available, and you can easily decide something within your range.
If you are coming to Karachi, then go to Tariq Road, and ask anyone about the AC Technicians shops, they will guide you to it. Its like mega street with only AC Techs over there which can help you out within your budget for sure.
3. What parts do you will change on the car?
Can;t answer that.
4. What kind of gas you will fill in the system? (R134a)?
I guess there are plenty of gasses available here, and yeah R134a is almost everywhere. & they are known by their country of manufacture here as American(the best so they say), German, etc etc.
5. What do you think will be the price for the complete work in Oktober-November?
I can't tell the actual amount but I am sure it will be solved within your budget, but do follow my advise, usually the shopkeepers jack the prices when they see foreigners coming. So do take second opinions through local friends to see if you're being charged right, do some hard bargaining...roam the market and pretend that this is not the first time you're here in Pakistan for work.
And stand at there heads when they are doing work. Satisfy yourself completely, and tell them you make to trips to this city every now and then just to keep a safe side.
I am not saying that everyone rips off, but its better to follow it then regret.
6. Where do you want to make it. City?
If you're coming to Karachi then go to the place Tariq Road(Its also a prime shopping street of Karachi with some of the oldest AC Technicians are situated behind it), PM me your arrival details and Ill take you to those shops if needed.
By the way, what is the name of this car in your country?
I have never ever seen this car here in this Country, maybe 1 or 2 could be around but they would be self-imports.