> what parameter in switch i should compare to total traffic in network, Switch capacity or packet per second
I hope you can deal with switch capacity (88 Gbps for your model) info as it is more explanatory and comparable to BW requirements. Forwarding rate with per packet info (65.5 mpps) is rate for theoretical rate with packets all sized as 64 byte long which is of course not applicable to real conditions.
but don't forget on to have corresponding uplinks per every SG200 switches in order to meet your criteria for connected number of user per SG200 switch.
