Create a Sitemap for Google with SEO considerations

We need advice on how to create the best [login to view URL] in terms of SEO results, and then create the sitemap for us. OUR WEBSITE Our website is translated in 4 languages, so the home of those 4 languages should be the most important pages of the map. We sell three services (in the 4 languages), and we sell them in each country of the world (190 countries). For each country-service there is a specific webpage. We have 6 pages that group all available countries. These five pages have the name of continent: asia, africa, oceania, america, Europe, multiregionals. Within each of these 6 pages we have links to each country (within that continent). We have around 2280 individual country-service pages, that come from 4x3x190 (4 languages, 3 services, 190 countries and regions). So if we sum the continent pages (72 that comes from 4 languages x 3 services x 6 continent) plus the individual pages (2280), we have around 2352 pages. Our Idea is to have 5 different .xml sitemaps (we are not sure this is ok in terms of SEO), first sitemap would have only 4 links, pointing to a specific language sitemap. Within each of the 4 language specific sitemap we would have links to the 6 continent pages (with more priority). And link to each of the service-country (around 570, which comes from 190 countries x 3 services). WHAT WE NEED We would need a provider that review our website, and suggest us the best way to build this sitemap and then build the sitemap for us.