Ok, how I said before is better if the PC take the IP from DHCP. Obviously, you can assign a static IP to the servers and administratives PC using the MAC of them. Is your election, but is better for administration and future expansion, the IP for DHCP that the static IP.
Another point, you have at this moment 95 PC, and 60 more the total will be 155. To this, add the printers, AP, laptop, servers.... Is a dedicated work configured the IP adress, PC by PC