Develop a Prestashop module to change the prices of the web according to the localization of the user

We need a prestashop module where the prices are changed based in a cookie/popup where the user selects his country. If he selects country a then an address in that country should be associated as a guest, then the prices should be changed as with the taxes associated to that country. If select the country b then the same should ocurr, the prices should changed to the ones associated with that country. Really the prices are the same, only the taxes are changed between countries.

We need the module to setup a cookie so the user selection is remembered for at least 7 days.