Any launcher which has a lock-on can be used to take down an enemy UAV or to restore your radar if the enemy get a counter UAV. Launchers which have lock-on are the AT4-HS (the very first one you unlock), the Stinger and the Javelin. The Javelin is the best as it packs the most punch and can lock on to vehicles and locations. But the AT4-HS is better than the Stinger if you ask me because you can free fire it and it does just a little less damage than the Stinger but the Stinger does however come with 2 rounds.
While it can be a disadvantage not having a sidearm, I think it's even better to have a launcher as it stops the enemy from getting UAV and keeps you with the upper hand. Just make sure you go somewhere far from where the enemy is as I've gotten killed a few times by looking up at the sky looking for the UAV Recon, doh.
Also thanks Bulletproof