NAB Transact Non-merchant Gateway for Blesta PHP

I require a simple non-merchant gateway to be written and installed into my Blesta v3 installation. The gateway is for NAB Transact (National Australia Bank). There are samples available for other gateways. I just need the order information to be sent to the NAB Transact hosted payment gateway, and for the response to be notified back to Blesta. Blesta experience preferred. Blesta Payment Gateway experience is even better. NO GENERIC RESPONSES - I WILL SIMPLY IGNORE THEM.