Hi crossroads,
Sorry to drive you crazy with all this stuff. I also have this ADC: http://www.digikey.com/product-detail/en/MAX1416EPE%2B/MAX1416EPE%2B-ND/1937385
And I noticed that it does a an AREF maybe this might be a better choice? But, it looks super complicated. However, I found this online: [SOLVED] MAX1416 SPI interface with Arduino - Networking, Protocols, and Devices - Arduino Forum
I'm off to bed and will review tomorrow.
Thank you so much for all your help,
Cameron.