Help on our project

Hi , We are developing a project under our university course . A
company has a central server and several branch servers. The company's
employees are on field within a 1 km range of a branch server. The
branch servers and the handheld device on the employees communicate
using wireless network WI-FI. Branch servers communicate with the
central server through internet.

Currently we have a ebox2300. we want to use it as a
branch server and also as a wireless access point.Simultaneoulsy it
will act to communicate with main server. We want to know whether
doing all these is possible using ebox and if not what changes need to
be made to ebox?

Which IEEE standard for WI FI can I use to cover range of 1
km ?Is it possible to use IEEE802.11 b for this?

What type of WI FI transceiver can be used for Hand Held
end device here?