I have an Authorize.net gateway and we want to setup fixed billing through Zoho Invoice.  The way our billing works is a client pays 50% upfront and 50% at a later date.  With the current Authorize.net placeholder the links brings the client to a page where they can't edit the amount they're supposed to pay.  I'd like the client to be able to edit the "Pay Amount" line in the Authorize.net payment area.

On a side note, I'd also like to change the text that is automatically added to the link of the Authorize.net placeholder.  Right now it says "Make Payment via Authorize.net" and I'd like to customize that.  Any easy way to do that besides editing each Invoice Notification Email.