Every agency I've worked at didn't have one overarching solution for hosting client sites. Some clients already had a relationship with a hosting company and di

Every agency I've worked at didn't have one overarching solution for hosting client sites. Some clients already had a relationship with a hosting company and didn't want to change it. Other clients had a huge legacy codebase that they didn't want to pay to have replaced and we didn't want to pay to migrate and host it. With every client, there was some weird new situation that we had to navigate. So rather than finding one solution, you might think about putting your client's sites into different buckets. Some sites might be a small one-off that you're starting from scratch, and those might fall into the shared hosting bucket. Some might be bigger or use a different stack than your typical site and those could fall into the VPS bucket. The remainder might fall into that unknown/unknowable zone, so it'd be good to plan out a way of managing third-party or client-hosted sites. I think it's a rare thing for an agency to start off a new client relationship with an entirely blank slate, it'd serve you well to be flexible.