DEFENTAC Green/IR Beam and White/Infrared Flashlight Combo(4-in-1) is Compatible with Mlok/Picatinny Rail, 1450lm Light with Remote Pressure Switch for Rifle, Aluminum, Rechargeable

This one? You really want to mount the laser up top, even if you have to pull the front sight way back. Here's why. The short version is that a laser mounted at the 12:00 position can have a battle zero that works within 2" out to 185 yards. A side-mounted laser is good for CQB only, offering no real redundancy for your iron sights at range thanks to the cross-range drift it will suffer. No shade on the cheap laser. I'm using this one, until I can afford a SMSlaser. The next upgrade you should be contemplating is probably a dot. Palmetto State has some deeply discounted Vortexes, which should be almost adequate, actually. (The PWM dimming on their Spark isn't butter smooth, but personally it doesn't bother me enough to care) That might set you back just $60, if I'm remembering right.