Android device for wifi development

Hi Guys,

I just stumbled accross this forum and so far it looks like a very useful place, so well done to all you posters.

Im just about to start on my 3rd (final) year BSc Applied Computing and for my project I am going to be creating a system for security operatives to be able to communicate over wifi (much like they would with the traditional walkie talkie system) however my device will also have an emergency button that transmits the location of the operative.

The reason I am posting on here is that I am going to be producing it as an Android app (as my supervising lecturer is a bit clever with Java and not much else :/) What I would like some input on is the device I should by to use as a development platform. It doesn't matter if it's a phone or a tablet. What is importsnt is that the manufacturers have left full access to the wifi api. I need to be able to scan as quickly as possible. Also, price is another constraint as i have a lot of equipment to buy.

Any advice would be very much appreciated.

Thanks

Dylan