This is a good suggestion. If you want to prioritize security and response speed over country of origin, I think the best implementation is as follows:
Stack the two tables
This would result in a table of HTTPS (which is the most useful protocol these days) proxies, with acceptable security levels, and are reasonably fast/responsive. You can then filter that table by country/region if you really want to.
please added this resourceful website as well. http://free-proxy.cz/zh/proxylist/country/CN/all/ping/all