This post is closed in favor of the duplicate linked above, in "Hardware". Hopefully you might get some hardware advice in that thread.
rahulnayak, you have asked a very vague, wide-ranging combination of questions. You will do better if you break the question into parts, for separate threads: Apache configuration is a topic in itself; load balancing is another, and clustering again is another issue. Do some research, come up with ideas, and present your ideas for opinions.