You should start checking Altiris.ASDK.NS.SoftwareDelivery.SWDSolnPackageManagementLib in the ASDK API Documentation. Its actually NS6 implementation but should work with the NS 7 packages. The NS 7.x Software Management Framwork SDK will only be ready when 7.5 arrives.
As discussed in the other threat you need to give some input for all the properties when you use SetPackageExPackageServerOptions as in
result = packageManagement.SetPackageExPackageServerOptions( packageObject.Guid, true, PackageServerGuids, "C:\Program Files\Altiris\Altiris Agent\Package Server Agent")
The interesting part will be to find out the Guid just created package/image and the Guid of the Siteserver its running on.