先払いの新店探しはで情報が早いのはこのへん
https://www.non-ridere.com/advice/new-service-bulletin
https://5tayon.com/
https://pays-first-purchase-service.com/
https://funkatsu.com/
https://mumbai-central.com/
https://toku-katsu.com/

先払い業者の系列情報はこのへん
https://pays-first-purchase-service.com/group-vendor
https://funkatsu.com/sakibaraikaitorikouza
https://5tayon.com/category/genkinka-howto

鬼電とか晒しとか業者の危険度は業者のなりすましカキコも多いので下を参考にするのがイイかも
https://www.s-syoshi.info/yamikin-list/list/tag/%E5%85%88%E6%89%95%E3%81%84%E8%B2%B7%E5%8F%96%E7%8F%BE%E9%87%91%E5%8C%96/