Which region should I pick?
The one closest to the people who open your site: EU-Central for a European audience, US-East or US-West by coast for North America. If the data has to stay in the EU, pick EU-Central whatever the audience. Three regions is the whole list — there is no Asian region today.
Does the region change the price?
The region does not change the price: a plan costs the same in all three regions, and it renews at the price you bought it at.
Where exactly are the data centres?
EU-Central, US-East and US-West are our own region names, and we don't publish the address of a rack. If you need the location and the operator for a compliance review, open a ticket and we will give them to you in writing.
Can I change region later?
It is a migration rather than a setting: the site is copied to the new region and the name is pointed at it afterwards. Tell support what you need and we will plan it — but it is easier to pick the right region at checkout.