Figure 230 btu's latent load per person. Then match it to the latent capacity of the equipment you're considering.
The latent load from body heat will almost always be larger than sensible heat from bodies or structure in any meeting house when compared to the capacity of the equipment.
The latent capacity of most modern equipment is about 25-28% of the total. So, 90 x 230 = 20700 / .25 = 82,800 / 12,000 = 6.9 tons. Call it 7 tons or 7.5 if you use a package unit. Keep in mind, this doesn't include any make up air which most codes will require. Usually 5 - 15 cfm per person. 90 x 5 = 450cfm. That's at least another ton if the 5cfm requirement is used.
You can choose to do what you want, but you cannot choose the consequences.
when you see these pictures of the chapel, you will see why we cannot use an ordinary approach to heating and cooling. http://www.forestlawnomaha.com/images/chapelpics2.htm
I want to investigate using a boiler and chiller with some [hopefully] innocuous looking cabinet fan coils. if I can raise enough money, maybe we could use geothermal, and not have a noisy condensing unit outside!--NBC