The single Integre only outperformed the Complete when powering hard to drive speakers. So the power supply in the single Integre must be superior to the Complete.
That said however, there is a used single Integre with the optional MM phono at Alternative Audio in Canada for CA$1250 (US$800.) They will ship to US. You can't get phono with the Complete and the Integre phono stage is very nice. So for the cost of a mint Complete you can get phono and a little better build quality. I am not connected to this dealer. http://www.alternativeaudio.com/useddemo.shtml