Vikas,
I also ned to ask how large of a infrastructure are you implementing? there are some memory, disk and cpu and node counts you need to consider besides the base imnage. I am attaching the whole netowrk sizing guide line. It spells out node count, netowrk traffic for the various monitors, from experience you do not want to short change hardware. You also need to consider is this going into a virtual enviroment also. let knwo if you have any more questitons.