My suggestion is look at the Columia River Knife (CRKT) M-16 Series. A very good design from Kit Carson. Liner lock w/ very good flipper guard, and 'auto-lawks' which keeps the liner lock from closing accidentally. Auto-lock and excellent guard might make this the safest folder made.
I like the SF model w/ double flipper guard, which I think could probably even be used as a 'wave. (make sure model you get allows for tip-up carry if you like this idea. My M16 is an older model, but it has been durable and a good EDC for me. Cost for most of them is in the neighborhood of $50. They have quite a few versions, so you can get exactly the one that appeals to you. Not made in U.S., but in Taiwan, a solid U.S. friend who needs all the help they can get to be saved from absorption by the Chicoms.
I like the SF model w/ double flipper guard, which I think could probably even be used as a 'wave. (make sure model you get allows for tip-up carry if you like this idea. My M16 is an older model, but it has been durable and a good EDC for me. Cost for most of them is in the neighborhood of $50. They have quite a few versions, so you can get exactly the one that appeals to you. Not made in U.S., but in Taiwan, a solid U.S. friend who needs all the help they can get to be saved from absorption by the Chicoms.