Engine Mounting Set

Vibrations and funny sound from the engine bay is very annoying and I hate these sound, I love when my car sound like a cat purr when in slow speed but roar on full throttle . My car used to purr when it is new but now after clocking 220k km, it sounds horrible and vibrate badly when the air-cond compressor is running. So I decided to buy and replace the current engine mounting as I never done so during the entire duration of 6 years owning this car.
The set consist of 3 engine mounting on the left, right and rear of the engine. Cost a lot but thanks to the local parts importer Sen Hui, the boss gives me some discount and I save some money for the labour fees later on.
I wonder it is normal practice to change all 3 engine mounting together or just change individually ?
Here is some picture of each item part numbers :-
11710-70H00
11620-70H00
11610-70H00

If you have the money, you can always buy the strengthen/enhance engine mounting set by Suzuki sport, which reduces engine movement during operation which resulted a better balance on the front weight but sacrifices the comfort a little bit because vibration will be transfer more to the body.

Links to their page :-
http://www.suzukisport-racing.com/news/040214swiftsp_engmount/index.html