A traditional handle bar bag like an ortlieb has the advantage of super easy access to stuff, camera etc, and ease of taking off to always bring in with you for stores etc.
From what you describe of roads, I've ridden lots on similar with no issues. Bikepacking bags will be better for lots rougher.
Have fun researching options, costs, waterproofness (priority for me), ease of removal.
Ease also of mounting either paper maps or GPS units etc,

you've got lots of options, although covid has certainly screwed up actual availability, so you may be limited.