Test reception before you drill any holes.
I've been successful using a similar configuration to you plan #1. In my case, I placed the UHF antenna at the top (not a hard fast rule... experiment and use what works best. I've used wall stand off brackets, but the type you show are fine. Use what best fits your mounting surface. I also installed a 10.5 foot chain-link top rail from the local big box home center. For some applications, three more feet is a significant factor. My install survived several storms with 60 MPH gusts. I've since sold that house do I don't know if the antenna is used by the new owner or if they have removed it.
Plan #3 is also quite practical.
But, Test reception before you drill any holes.
Plan #2 looks like it would work well. I wouldn't fee the need to spend the extra money though. And once more just to sound preachy...
Test reception before you drill any holes.