Electricity for Legal 3-Family (2 part question)

We need to update the 3wire meters and update to 4 100 amp rated boxes that feed our legal 3 family as well as the ConEd end line box. The service is 100 amps and we are not planning on going to 200. Question 1: What should we expect the cost of this job to be? Question 2: Is 100 amps enough for the 3 family which will be used as a 2 family? (we don’t plant to install an HVAC, and water heater/heat/dryer/ovens are gas fed). The only major applicaces would be 2 fridges, 1 dishwasher, and 2 or 3 A/C window units and a possible future upgrade to 1 or 2 of those wall air conditioning units. We are leaving as a 3 family in case someone down the road wants to use it again as a 3.