you would need to edit the power store theme template to match the store design.
to create a custom theme, you would need to make a duplicate of one of the existing theme folders.
go to webassist/themes and select a theme as a starting point, copy it and save it as webassist/theme/<your theme name>
you then need to edit the webassist/theme/<your theme name>/templates/index.dwt.php and page.dwt.php files to your design.