Hi, I'm working for developping a payment gateway (Systempay), and I would like to offer payment by instalments. My problem is, the gateways works by sending a form to a URL which is external to Cubecart, and the choice of paying all-at-once or by instalments shall be made when sending the form. Therefore I need, on Cubecart's check-out page (www.mywebsite.com/index.php?_a=checkout) the customer to be able to choose to pay all-at-once, or by instalments. Today I offer a setting to allo