As someone mentioned there is no gravel in Newport Beach. Actually, I know of no real gravel anywhere in SoCal west of the mountains. Don’t know what is happening in high/low deserts.
If you are riding from home you will either go up the coast to HB, where it is flat, or you will be riding in hills.
You need to pick the bike that matches how/where you ride.
I think someone posted a gear calculator which can give you speed at a certain cadence (rpm). Figure out what range you need.
As someone else noted, no one know how you ride, so the suggestions on what is best really don’t apply.
John