There are two types of snipers in Black Ops: Bolt Action and Semi-Automatic. My suggestions for quickscoping would be to use the L96A1, the only bolt action in the game, However, if you would rather play more realistically, the PSG1 would be the way to go. 

Secondaries. My recommendation would be any pistol. Each pistol has its own pros and cons. If yuo want to be a little more daring however, I would use the ballistic knife.

Attachments. For your primary the best attachments would be either the variable zoom scope or extended mags. Either of these attachments are good, it just depends on if you like the original scope or not. Both of the attachments are on all of the snipers. For your secondaries, the M1911, Makarov, and the CZ75 all have the same attachments. The ASP and python however, do not. The Asp's only attachment is dual wield. The python is unique in that it has the option for an ACOG sight (Which is surprisingly good), a snub nose, a speed reloader, and the ability to dual wield the weapon. The other secondary I mentioned was the ballistic knife. This has no attachments.

Perks. A lot of people suggest a wide range of perks. My suggestions are to just use whatever perks you feel the most comfortable with. Personally, I use Ghost, Hardened, and Ninja. Again, perks are more just a matter of your preferences.

Killstreaks. Personally, I use the lowest killstreaks possible. I use the spy plane, counter spy plane, and either the care package or the napalm strike, depending on the map I am playing on. It doesn't matter as much which killstreaks you use as long as you think you can get them, Hence if you don't think you can get attack dogs with a sniper, then don't use them. But, if you think that you can, well, why not?

Lethal. I recommend using the Tomahawk. It can be used very quickly and doesn't take long to take out. The only down side to this is that you have to be very accurate since you only have one (Unless you have scavenger). 

Tactical. I usually use nova gas. If you want to get really tactical try using the decoy. However, all of the tacticals are useful if you use them right. This might take some experimenting to find which one works the best for you.

Equipment. All of the equipment are useful like the tacticals. I use either the motion sensor or C4 depending on the game mode I am playing. As with the tacticals, experimenting will help you decide which equipmet you prefer the best.

Camos. These are entirely up to you. You unlock the gold camos at prestige 14. However, they are 50,000 CoD points.