Sorry I don't have any specific information, but just a suggestion. Why not call the contractor that was doing the job? Sometimes these things are proprietary to the contractor, but it is also possible he purchased it and would give you the lead.
The other thought would be to call a number of auger cast pile contractors in your area and ask them.
Unfortunatly the problem with that is that the machine that I worked with before is located in the UK and the company is now not doing business. I have heard rumour of a machine that utilises pullies and chains to space the bars but I have never come across one. Any help with this matter would be greatly apprcieted