You are not writing the specifications for your VPS, but your best bet is to do a benchmark to check if you can handle a certain amount on http connections.
Check out som of the benchmarking tools below.
[1]: http://httpd.apache.org/docs/2.2/programs/ab.html
[2]: https://github.com/tarekziade/boom
[3]: https://github.com/wg/wrk
