Sharepoint with SQL Always On

What is the business case you're trying to solve?

The first option looks like a Stretched-Farm and the second option is a traditional DR farm approach.

I'd suggest to create the backups from your primary farm because it will probably run with Full Recovery model in SQL and the proper backup strategy will help keeping the transaction log's storage need low.

I suggest to take a look at this article Stretched SharePoint Farms vs. Disaster Recovery SharePoint Farms and follow all links in it as well.

And also read this longer guidance as well:

Create a high availability architecture and strategy for SharePoint Server