Your power needs to sized using the power plates on the power supplies in your switch. If it says x amps at 220 then that is what you should put in.

You can always put in more but you should never put in less. Many electrical codes require this also. Now the actual power it takes is related to the types of cards in the chassis and if the power supplies are both using power at the same time etc. So you could put in less and it fine at least until someone puts in a new board and trips off the breaker.

From the sounds of it the circuits you are going to put in are large enough since most the power supplies only want 16a max. The largest ones seem to just have more plugs rather than larger single plugs