Welcome to the forums,
sorry, can't help with the vps
things that control your speed are
your in house set up, [best is hard-wired to the router not wi-fi]
your sync speed [between you and your provider]
the network speed of your provider,
the load and speed of your network server
the international transfer speed
and the speed at the customers end
If I had a sync speed of 500mbs, and you only have a sync speed of 24mbs, then the fastest we can talk to each other would be 24 mbs
This isn't really a topic suitable for this forum - but I have some input. I'll answer and move this to 'off-topic'.
Digital Ocean isn't bad. You'll get good speeds, based on where the client connects from.
Just sign up for a CDN and you can increase your local speeds by providing local mirrors of your content. You can pay for it or you can just use CloudFlare's free tier. There are other CDN solutions, including free tier options. Just search at your favorite search engine.