Wattz Laser rifle has higher damage than AER-9 Laser rifle, has slower firerate, can be transformed to automatic or semi-automatic weapon on any workbench without need to change barrel or receiver. If you feel that it has not enough damage for sniper shooting, you can find a unique gun that will add ballistic damage to rifle, making it one of the most powerful semi-automatic weapons, standing in one line with Gauss Rifle. This option can make this rifle the strongest energy weapon in game. The rifle will appear in game after level 15-20 at vendors and hi-tech factions like Institute, BoS and Gunners.
If you can't get it from vendors or enemies for some reason, or you want to get it faster, there are few uniques placed in world, you can also find non-unique Wattz 3000 rifle in Wattz Electronics store. For your personal taste, there are few non-unique paintjobs, but if you want to be special, be ready for treasure hunt. But first, help find missing people, investigate old irradiated vertiberd crash and be Institutionalized