Recommended ethernet topology for buidling complex

Though I am a simple network administrator, one of my clients is growing by "leaps and bounds" and building 20, new, one-story simple buildings for a flea market with each building having about 50 booths and some food stands. To save, he wants me to design and install the network, with the aid of his people running the cables and conduit; I'll terminate. Each building needs to be connected back to main office and each will have at most 4 computers, 4 voip phones, 4 ip cameras, possibly a DVR with 16 analog cameras and hopefully 2 outdoor paging speakers over ethernet. The buildings are very tight together. The current plan is to run one 2" underground conduit and connect about 6 to 8 buildings with it. Then install Gigabit Switch at each building. At 6th building, have fiber run back to office, hopefully in separate conduit. Then Cat 6A to the rest of the buildings within 328 feet. Then Cat 5e or 6 to each device in the building. It just sounds difficult to snake those 6 buildings in that one conduit. So Option B would be to just daisy chain the switches with Cat 6A or Option C - Fiber. My questions are - 1. What design do you recommend? 2. Suggestions on where to get materials - fiber, cleaver tool, gigabit switch, FI, enclosures. These rooms will not be air conditioned, really an outdoor scenario, so equipment has to be durable. Thanks for any input...