Long range Wireless setup with standard routers found in Retail Stores

Here's the current project that I'm working on with a friend. For starters I'm trying to make this work with the equipment we have. Which is the following:

Belkin F5D8231 Router http://belkin.httpsvc.vitalstreamcdn...8231-4_man.pdf
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Linksys WRT350N Linksys.com - Support/Technical Support/Choose a Product/Specialty Products/Network Storage/WRT350N/Downloads
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Belkin Wireless N USB Adapter

Layout of Locations:

At the moment I am not getting any signal...I was thinking about probably placing the wireless linksys n router in between and setting it up as an access point that will connect to the belkin and transmit the wireless signal closer to the office. However I'm not sure that is possible with the current equipment. Anyone have any suggestions or recommendations as to how to get a signal. I understand there will be a significant drop in speed, but as long as you can browse online and load pages faster than dial up then that will be fine. Most of the internet downloading etc, is done in the main location that is wired.