Sell eBooks hosted on Amazon

On a site that offers books, both physical and eBooks, how do I offer a product hosted on Amazon, iTunes etc from Hikashop?

Forgive me if this is covered already, but searching the hikashop forum gives:

o valid database connection Table 'hikashop.jos_fb_categories' doesn't exist SQL=SELECT c.name AS title, c.description AS text, c.hits, c.pub_access, c.published, '' AS created, 'Forum' AS section, '2' AS browsernav, CONCAT('index.php?option=com_kunena&Itemid=', '', '&func=showcat&catid=',c.id) AS href FROM jos_fb_categories AS c WHERE ( (LOWER(c.name) LIKE '%amazon%' OR LOWER(c.description) LIKE '%amazon%') ) AND c.published = 1 AND c.pub_access <= 1 ORDER BY c.name DESC LIMIT 0, 50
No valid database connection Table 'hikashop.jos_fb_messages_text' doesn't exist SQL=SELECT b.subject AS title, a.message AS text, b.hits, c.pub_access, c.published, c.description, FROM_UNIXTIME(b.time) AS created, CONCAT('Forum','/', c.name) AS section, '2' AS browsernav, CONCAT('index.php?option=com_kunena&Itemid=', '', '&func=view&catid=',b.catid,'&id=',b.thread) AS href FROM jos_fb_messages_text AS a INNER JOIN jos_fb_messages AS b ON b.id = a.mesid INNER JOIN jos_fb_categories AS c ON c.id = b.catid WHERE ( (LOWER(b.subject) LIKE '%amazon%' OR LOWER(a.message) LIKE '%amazon%' OR LOWER(b.name) LIKE '%amazon%') ) AND c.published = 1 AND c.pub_access <= 1 ORDER BY b.subject DESC LIMIT 0, 50