Domain Name Reseller API plugin advice

Hi,

I have a domain name reseller account with a domain registrar here in Australia... NetRegistry.

They provide a reseller API to manage domain names through our account and as I have never jumped into any custom Wordpress plugins before and development time is not really available... can any one point me in the right direction as to where I would start, or if any plugins/sample code already exist for this sort of thing?

The reseller API documentation for my registrar, which contains the required PHP code for communication to their system, is located here

Also, ultimately I'd like to incorporate this domain API into something like MarketPress and Pro Sites, where a user could check for an available domain name, and then add that to the cart and add additional hosting/email options as well before checking out.

Thanks,
Kent