I have a guy who handles all my skip tracing, found him off of Fiverr. He’s been my go to for awhile now.
He has a team so turnaround is quick and it’s manually managed which i like because they’ll find LLC’s as well. He uses TLO and Locateplus. Anywhere from 1-7 numbers per lead.
Quality numbers at 15 cents a lead (hard to find much cheaper). Any size list.
No one will ever find 100% of the list but assuming your data is correct and correctly laid out, my guy should be able to find 80% and up.
Shoot me an email if interested, thanks!