S-100 power supply transformer

Hi! Does anyone know of an available transformer suitable for making an S-100 power supply? I need 120VAC input and 10VAC output and +/- 18VAC outputs. The best I solution I can find is two separate 80VA transformers; one parallel 10VAC output and another 36VCT output which can be configured for +/-18VAC outputs. I would prefer a single transformer rather than dual transformers because they are the most expensive part of a linear power supply. I know Northstar and Vector Graphic used similar dual output transformers but I cannot find anything like them after searching the usual vendors like Digikey, Mouser, Jameco, etc. Even transformer manufacturers don't seem to carry a stock product of this configuration although you can order custom units. Thanks in advance for any help. Your ideas greatly appreciated. Thanks and have a nice day! Andrew Lynch