Crimson, less snag if you need to pull it out for any reason

I looked into getting a laser site for my PT111 G2 and either the Crimson Trace CMR-201 with a red laser or the CMR-205 with red laser and 100 lumen light to be the best options for attaching to the rail underneath the barrel. The only drawback is that no one makes a formed kydex holster that will fit the PT111 with either one of those attached. If you're fine with a different type of holster then those two Crimson Trace models mentioned above will work out the best for you. There's also ones with Green lasers but are significantly more pricey.

crimson trace is the right choice eerytime

Crimson trace makes a laser for the PT 111 and free battery's for life

I'm a fan of the Streamlight TLR-4 laser light combo. I think it would be perfect size for a pt111