IIRC the hinge makers recommend that the hinge size should be one-third the gate width. I like galvanised hinges and paint them myself. Due to coastal area I use stainless screws and coach-bolts, with domed or acorn nuts for added beauty.
The gate will doubtless sag a bit over time, despite the use of diagonal braces. You can gain fractional height later by slipping C-form greased stainless washers over the pin. This also makes them swing better without wearing the hinge parts. A jockey wheel at the opening side will also help.
I have sometimes considered a stainless threaded rod to link the top of the hinge stile with the bottom of the latch stile, but have never got round to trying it. My next attempt will be to swap a gate to hang on the opposite side for a bit to let it go the other way, and adding a tensioner. When it sags, your previous bolts and latches no longer fit, unless you used a very long staple.
I think the "hooks to bolt" are a more durable design than the hooks on screwed plate.
if you can join the tops of the two gateposts with a simple lintel, it will prevent them leaning together.
