If it's a standard 92fs, the front sight will have to be drilled to accept a night sight dot. Tooltech gunsights can do it for about $110. You send them your slide, they'll drill and install trijicon vial in the front and put a full set of triji night sights in the rear. I did it for my patrol pistol. I had yellows in the rear and green up front. They did it and had it back to me in a week. Google tooltech gunsight.
weather you install lasers, which take an extra second for the brain to realize their position on target, or tritium, with dots so small they make the acquisition of target a real pain, the standard sights of your handgun are all you need.
You could enhance their performance by adding GID (glow in the dark) markers like this ones:
Which don't modify your training with such a weapon but shorten the time between presenting, acquisition of target and deliver.
I used the products from glow-on.com, is a plastic polymer, really hard and luminescent when dry, I don't have a big budget either so twenty greenbacks seemed OK, and I still have some for my rifles