Mangos even works fine on a P3 Dual Server (Well it cant hold much players but 50-100 are no problem depending on the settings). The problem here is not the hardware itself, its your bad knowledge about servers and Mangos itself. Your server can run Mangos fine and adding even more CPU cores will not help you at all, use the search function here and inform yourself first.
I guess that you are using 64bit Linux cause Windows is really not acceptable at all together with Mangos, so configure your system first with tutorials like this one http://www.linux.org/lessons/beginner/index.html you may have a chance then to get in 1-2 months a stable server.
Oh and it is not a good idea to talk about such topics here cause public servers are in some countries not completely legal, you should remove the root advertisement else you might get banned.