In my experience a real "ofshore team" is a nightmare, and hiring an intermediate company messes up the loyalty of the team members. You are a customer of their boss, not their boss, and they can tell their real boss that you are impossible to work with/for and be reassigned to another client, disrupting continuity.

A better option is to anchor your team with a Product Owner and potentialy a Scrum Master or equivalent agile role that are anchored in your company and the local and business culture. Then individual team members can be contracted from whatever country as (mostly) remote workers, but your PO or PO+SM will anchor your team.

As for remote team members, Codeberg and Github are your friend. Not just as a way to validate that a candidate is of the caliber they claim to be, but many open source projects, big or small, will do part of the functionality you need, or "almost" what you need. Instead of a pure contracting contract with the team member, start off with funding your own open issues or open issues or roadmap items to be prioritized in the open source projects you use. Your experience with these issues being addressed is golden for building up relationships with competent devs that you might later want to add to your team. The more your work for them touches the open source work they are doing, the more commitment and above and beyond attitude you can expect. You aren't just an employer, you are a sponsor of their passion.