It depends, dose your your sniper have threds?
Type airsoft sniper silencer on Google and you will get something.
You can find many kinds of airsoft AEG's silencer at any airsoft store nearby. Make sure the thread is exactly the same (clockwise/anti-clockwise) with your AEG's outer barrel.
No silencer is going to actually "silence" your airsoft gun since the sound is coming from the gearbox, not the barrel. But a good place to get a mock silencer would be Airsoft GI and Evike.com
You must be atleast 18 to buy airsoft guns and accessories.
try crw-airsoft
Buy the one YOU like.
Buy a decent sniper rifle (gas or spring) a scope if it doesn't come with one and then practice.
put a silencer on it
Airsoft GI www.airsoftgi.com
you will never go wrong if you buy the best you can afford
Yes. You can get replacement springs for airsoft sniper rifles.
There is no most powerful airsoft sniper rifle that you can just buy. But, Iv'e heard of guys tuning them over 800fps with custom parts. My most powerful is 600fps.
A silencer should go on the muzzle
any sniper with a silencer