Chassis versus Stackable

I have just be handed the responsibility of designing the LAN inframstructure of a new manufacturing building our company is expanding into, something that is a first for me. The estimates right now, is the building will roughly cover 250,000 to 300,000 square feet, with about 4 wiring closets to start with. The new building will start out small for the first couple years, with about 100 or less end nodes. I plan to use Gigabit in the infrastructure. Which would meet the requirements to start up this new building and allow for future expansion, chassis or stackable? All while retaining redundency. Cost, as it always is, plays a big part in this. Any suggestions would be greatly appreciated.