to answer your title question. A good sniper is someone not something so a gun doesn't matter, I have "sniped" with my PPSH-41 before
Onto what you ment lol.
the VSR VS the L96. The trigger set up in the VSR is just... horrible. Terrble terrble terrble. A lot of pressure on something not much thicker than your little finger.
The l96 trigger system is basically the zero trigger already installed.
When and where are you using the gun? Gas could be an option HOW EVER it is limited to warmer weather use. Now if you wanted versatility you could always consider a DSR-1 as they do come with a spring and gas bolt. Thats going to run you more than the SVD though.
Also were you wanting a single shot sniper or have you looked at AEG based sniper platforms? IMHO the mechbox is a bit easier and cheaper to upgrade especially if you get a v3 platform. Also you don't need to reposition after every shot. You can get a Mosfet unit to force 1 second intervals between shots. A SVD is a good option here, ... ar based one... frick can't remember the # at the moment. Or if you want a PSG1 how ever upgrades can get expensive for that as its a version 4 and the only gun that uses that mechbox set up.