If you're expecting traffic growth of that scale, I’d look at a provider that gives you both vertical and horizontal scaling options without forcing a full migration later. A VPS is fine for the first stage, but only if the platform offers strong uptime guarantees, daily backups with long retention, and the ability to switch between plans fast. Something like hostpro.com can work well because they run on NVMe storage, keep 30-day daily backups, and let you choose locations such as Tampa, Amsterdam or Warsaw depending on where your users are.
Their environments handle PHP/MySQL smoothly and you can manage everything through cPanel, DirectAdmin or even Plesk if you prefer a more enterprise-style workflow. With 24/7 support and easy scaling between VPS tiers, it gives you more stability than cheaper VPS brands.