Okay, if your missing the targets. You need more practice time shooting, I will easily spend 2 to 3 3 days a week just shooting and go threw 1000 rounds in a day. But when I do play I will take 2 mags, the one in the gun the other in a pocket or pouch.
As for new guns, if you like the sniping go with something that is a DMR such as the M16, or M14. It takes time, practice, and patients to become a good sniper. On top of that you need to have a quality gun, with some upgrades. Your probably missing your targets because your not taking the time to line up the shot, you your gun/scope isn't adjusted right.
As for it being a woodland BDU, and if your basing it around that, go with the a boonie hat, and try to do a Navy Seal set up. Since the seals set ups changes to work with what there mission calls for. I would say go with Woodland BDU, Woodland Boonie hat, jungle boots (or any other black boots that you like) and a chest rig. It is light, fast to get on, and does it's job.