Building a swinging garage/barn door

I have a single detached garage that needs new swinging doors. Each one is 4'x8'. Nothing fancy just looking for it to be functional and lockable.

The existing door was 1.75" thick single frame of wood.

I'm thinking of doing 3/4" plywood backing, 1/4" vinyl wall paneling for look, 3/4" wood or pvc trim.

Assuming the hinges are sized and placed correctly, will I have any sagging issues down the line?

Another option I thought of was 3/4" birch with 1" milled poplar as the trim either biscuited or kregged together. More expensive option.

Thanks.