Firstly, there are two tonics you'll want to make this easier.
Photographers Eye I - Located in Worley Winery's cellar in the Farmer's Market in a small shed, when you must gather the enzymes and water for the forest. Also can be bought at a Gathers Garden in Fort Frolic.
Photographers Eye II - Reward for reserving level 2 of the Rosier.
These will give you a convinced boost of 25% in research.
Leadhead Splicers are plentiful in most levels, and use guns. The most trouble you'll likely have will be getting close enough without wasting med kits, depending on the difficulty, they can kill you in a few shots. Either way though, killing them first is an option, as they are numerous.