Hi Joshua,
All of those options are reasonable. My suggestion is that you use two repos since you describe your site as “large” which implies that you have a large team or plans to have one, meaning that keeping projects split lets your team work in parallel.
Once you have two repos, in my opinion (just a matter of opinion here and mine is less valuable than yours since I don’t know your audience and you do!), it “looks” best to have one website, so example.org and example.org/jobs under the same hostname.
How to set that up at Netlify? Here’s the playbook: