how do you optimize the server (eg. apache, php...etc) to let it have the maximum performance??

I would suggest having a read through the Technical and Security Tutorials thread.

well buy the best equipment and control panel... and get a really smart guy lol

Does ssh sound familiar to you? If not,

I suggest hire a 3rd party company to optimize your server.

Alternative is to learn from scratch and as adam suggest, check out the tutorial section for learn the basic setup.