If you want an all metal traditional frame style look for Bosch direct connect. All metal frame and has the pin style hook up built in. That little connector is plastic but I've never had one fail. If you want a beam blade style then look for Bosch Clear advantage, which also has the pin style connector built in, of course those beam blades aren't all metal, they are some kind of voo doo plastic and rubber, but they are a good blade.
Here's my 2 cents on blades. I switched all my vehicles to Bosch clear advantage about 10 years ago. On some of my rigs it was an upgrade and they worked great, on others they didn't work so well. My square was one of them. For whatever reason I could never get them to run quite, even after adjusting the arm to be sure the blade hit the windshield square. IDK, maybe it's because of the windshield shape. My arms are new so it's not lack of pressure. So I'm back to traditional frame style blades on the square.
16" was factory, and I also ran 18" blades for a few years. I didn't like the fact that if I ran the squirters on a dry windshield the motor (also new - no not rebuilt, new) so the motor would run sooo slow until it hit the fluid. Also seemed like I had more streaking and noise issues with the longer blades. Went back to 16"ers.