Integration to Salesforce Sage 100 Contractor


We are trying to integrate with Salesforce and went with Commercient to do the integration.  They keep insisting the bi-directional Sync needs the SDK (Salesforce to Sage), but when looking around could not find it.  When we speak to Sage they said they don’t supply this anymore except for development partners.  We don’t really know if anyone had run into something like this?  Any ideas or suggestions or feedback to anyone that has done this..... are we forced to become one time development partner to access the SDK?