You can use ordinary round-head wood screws. Or coach screws which are tightened with a spanner.
Use a large size and drill pilot holes. No.10 (5mm) or bigger. Due to the large holes in the plates, you can put stainless washers under the screw heads if you want.
What are the dimensions of the frame, and the stile or ledge on your gate?
The bolt you show is designed to be secured with a padlock. The Squire 660 has the best resistance to weather, rain, rust, corrosion and jamming. Cylinder locks are nowhere near as good.
If you think someone might try to break in, put one at shoulder height and one at kick height.