The bumpers are not easy to find. We get decent quality locally manufactured bumpers in Karachi. They cost around 20 thousand a pair. Maybe less.
When you say the car needs repaint, its not just that. There's rust all over which needs to be handled. Expect around 60 thousand at least for the complete body work.
Interior work usually costs around 15 to 20 thousand depending on what materials are used and how damaged the seats are.
When you've gone through all this trouble, you would need to put in new wiring. That should cost around 10 thousand if regular quality parts used. After that, when you're going to put the car together again, you would need to replace many parts which include new window seals, fender beading, bumper grommets, etc. Now you would also be required to put in all the parts that are missing which might include the entire chrome trim that runs around the car, dash board parts, emblems, and many other little things. Costs for these things vary according to each car. But keep around 50 thousand for all this. Parts that are not found can be imported which will raise the cost considerably. If you need new tires, that's another 20 thousand.
Keeping costs at the minimum, you need at least 2 lacs to do the job the right way and to put together a decent looking car.
I have not heard of anyone switching gearboxes looking for comfort. The beetle is one of the most comfortable cars. People who find it problematic and uncomfortable should blame themselves for the hack job they did on the car. You should also refrain from any local jugaars or modifications because that's a guaranteed headache. Feel free to post any queries here or the VWCOP thread. Do post pictures of the project.