If you want a top grade sniper rifle, buy a VSR 10 and upgrade it.
If you want a good out of the box sniper, I'd go for the Warrior L96. It's quite a good gun, but it's got a few inconsistencies and isn't as upgradeable.
However, I'd like to defend the Warrior - it's not rubbish as some people say - by inconsistencies I mean that firing 10 shots at 25 yards I get a spread of 9.0 cm (distance between centre point of 2 furthest apart shots), and the best 5 shots have a spread of 4.8 cm. Compare that to a fully upgraded VSR where you'd get a spread of 5.2 cm and the best 5 shots having a spread of 3.4 cm. Or compare to a .22 Anschutz, where you'd can't measure the spread with 10 shots because you can cover them all with a 2p coin.
So Warrior is decent out the box, but probably a VSR.