The question to allocate harddisks on specific SCSI Id addresses is occurring quite often (MSCS Clusters, legacy apps...)
This can be done through the vSphere API ReconfigVM method, but seen the frequency of this requirement popping up, I suggest to add the Bus and Disk Ids as parameters to the Harddisk cmdlets.
In my opinion this belongs to the 80% that shall be covered with a cmdlet.