Help on our final year project- please reply quickly

Hi , We are developing a project under our university course. We are novice in the field of wireless communication.We developed a web site
& we want to deploy the updates of that websites to our client. To deploy updates we provide hand held embedded device to clients. We assume that all our clients are within 1.5 km range. Currently we have an ebox2300. We think that we use this device to receive updates from website through GSM network (mobile phone network)& then updates will be deployed to hand held devices through WI-FI network. That is, ebox 2300 is connected to GSM network & local WI-FI network . 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 we use to cover range of 1.5km ?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? Remember that cost is a great factor in this project. Please give necessary information & links.
Thanks in advance Babu
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