Wireless Network in a Warehouse Help

Hi,

I have a warehouse which is approximately 90m x 30m which i need to equip wirelessly. There will be approx 4 PC workstations and associated printers at the left end hard wired to the incoming comms cabinet (which is connected to the server in the offices by fibre optic). I need to equip future workstation expansion wirelessly, as the warehouse staff will use PDAs. The ceiling is approx 10m high and has three ridges like /\/\/\ - there is metallic racking from floor to ceiling and into the ceiling voids created by the roof shape.

How would i be best to use wireless technologies? I have though about three wireless access points at the top centre of the building, bottom centre and middle right connected to a wireless router on the middle left (hardwired into comms box) as below

________________________________________
[                                   ap                                      ]
[                                                                             ]
[                                                                             ]
[comms                                                                  ]
[wr                                                                     ap]
[                                                                             ]
[                                   ap                                      ]
---------------------------------------------------------------

Where comms is the comms cabinet, wr is the wireless router, and ap is the access point.

Any direction regarding standards, even makes and models would be most appreciated - my knowledge of wireless is fairly sketchy

Thanks

Wesley