A basic question on Endeca I suppose. The scenario is we have a commerce website that running on say, ATG Search (or any other search) & we need to move to Endeca. Is it possible to just use the guided selling aspect of Endeca or is it mandatory to use the experience manager also? 

A second question, if we have to use experience manager then does it mean that the page layouts of the current site would have to change or can they be retained?