For this configuration you can use web server you like, I decided, because I work mostly with it to use nginx. Generally, properly configured nginx can handle up to 400K to 500K requests per second (clustered). Most what I saw is 50K to 80K (non-clustered) requests per second and 30% CPU load, of course, this was 2 x Intel Xeon with HyperThreading enabled, but it can work without problem on slower