[Gerrard]

If you pick a sniper weapon as your primary weapon, you get the ghillie suit. Whether you get it when you pick it as secondary weapon, I am not sure (you can just swap it around in that case). Note, you need the Overkill perk to use 2 main weapons.

To be honest, you will see people use the same handful of perks all the time. Snipers will usually have claymores as their first perk; beginners use RPGs. Later on, extra grenades is popular for spamming them. Most people will use either Stopping Power or Juggernault as their second perk, occasionally you'll get someone use a UAV Jammer. Hate when people use the Last Stand perk, and someone else gets your kill! Martyrdom works very well on close quarter battles (Vacant, Shipment, Wet Work). Deep Penetration works best with LMGs and sometimes Snipers.

Personally, when I was working upto Lvl 55, the best way is to stick with a weapon in a class until you get the 150 kills. You get 3 XP bonuses (100, 500 and finally 1000) and the add-ons. However, I never bothered with snipers on the PS3, as the maps didn't generally suit my sniping ability (kill cam and the fact the teams rotate around the map usually, rather than holding and end). Check out the various challenges as you unlock them and modify a class or two to help you complete them. Eg, using a silenced weapon, or killing people who are stunned or flashed. Misery Loves Company is an amusing one to try and do!