api domain registration / plesk

Hello we have a api ( manual) for domain registration, we need to get working exsamples ( php class ) a manual explaining all how to when they have the exsamples a stop befor registration when they use a order form so all info goes on hold till owner say aprove then handles make registration etc all is connected to a webinterface ( you get a test account to see working) also a connection to plesk when people order and it is aproved the name is added in plesk dns and client can select his own packages add username pw etc So a complete basic package what will make it 99 procent easy for them to use the api etc also a whmcs api we have a working version but many options mis, so a quote for total packages. i am now investigate the options and posibilities