From my experience in South East Asia, not all ISP are having good route peering. For example connection from South East Asia to China will result to high latency to some route connection.
So, you need to know which datacenter are good to host the server/application. They can use VPN or you can provide proxy but yeah this need more effort on this.
About specification, dont bother so much about it, use cloud server and you can easily upgrade the specification if needed. Windows based OS usually need higher specification compare to Linux based.