Please note that all the payment plugins that we developed are already included in HikaShop. You can configure them via the menu System>Payment methods by clicking on the "new" button and then selecting your payment plugin. For payment plugins developed by third party developers you'll need to see with the developer how to purchase/download/install/configure the payment plugin.
HikaShop.com is not affiliated with or endorsed by the Joomla! Project or Open Source Matters. The Joomla! logo is used under a limited license granted by Open Source Matter the trademark holder in the USA and other countries.