Yes, they will have the same attachments. If you want to switch to a different carbine you have to buy them again, though.
Planetside 2 is a teamgame. On your own, you are always an easy target against ESF - Empire Specific Fighters, i.e. Scythe, Mosquitos and Reavers - and Liberators. You need to work together with a squad to deter aircraft, otherwise your best bet is to hide in a building and hope they go away.
Apart from friendly ESF, Burster MAXes are currently the most effective aircraft deterrent but a single Burster MAX will quickly get picked off by experienced pilots, especially if you only have the one default Burster arm. You need at least 2 Burster MAXes using both Burster arms to scare away ESF and 3-4 against Liberators.
As a beginner, search for the protection of a platoon, you won't be able to deal with aircraft yourself. When you shoot them with your one Burster arm, ESFs will still unload their rocket pods on you before they move away to repair and Liberators will laugh at your tickling and continue to bomb everyone in range for several salvos before they have to return to a base to repair.
This might sound unfair and make ESF and Liberators appear overpowered but it is by design and in the spirit of the game. It is a teamgame, you should not be running around on your own, and Burster MAXes scale incredibly well with numbers to a point where 6 Burster MAXes can defeat an infinite amount of aircraft as long as they have an engineer providing ammo.
If you are alone, your only option is to get your own ESF and try to fight them air to air - no matter what others say, default ESF loadouts ARE able to 1v1 upgraded ESF, i've done it myself and i'm not even a good pilot. Ram enemy ESF if you can't fight them, it's a common and valid strategy.
For completeness sake, the purchasing options:
For Lightnings you can purchase the Skyguard Cannon... but don't. It's weaker than a Burster MAX and currently considered completely useless. It's nice if you have a few of them in your armor column to deter aircraft without having to stop and have Burster MAXes hop out of and back into your Sunderers all the time but unless you have a lot of them, you only have a tiny chance to even hit any aircraft.
For Heavy Assaults there are two different launchers you can purchase that can lock-on to aircraft.
Depending on the faction, the first is either the "Hawk GD-68", "ASP-30 Grounder" or the "Nemesis VSH9". They all perform the same and do less damage than the default Rocket Launcher but can lock-on to aircraft and so have a better chance at hitting. They also still have the dumbfire mode of the default rocket launcher against ground vehicles.
The second is the Annihilator, which can lock-on to both aircraft and ground vehicles but does even less damage than the empire specific anti-air launchers. It also doesn't have a dumbfire mode, so you always need to lock-on to ground targets which takes a few seconds. On their own, neither of the HA rocket launchers really prevent aircraft from destroying you, they just flare your rocket and then kill you before they start to destroy everything you hold dear. However, in a group together with Burster MAXes, they can become effective.
In summary:
- Find a platoon.
- Find a platoon.
- Find a platoon.
Best Answer
You do not purchase helmets, you purchase skins for your helmet.
There is no stat effect from any of the skins for any piece of equipment or vehicle other than possibly helping you blend in to your surroundings when you are trying to be covert about your actions (white clothing on snow, green clothing on grass, etc.). This may help you not get noticed and therefore not be as likely to get shot at but it does not protect you in any way when someone is shooting at you.