I hope to perform this upgrade this winter as well. Ironically, I was in to my marine supply Monday to enquire about the Jabsco electric Lite, and they quickly suggested the Elegance for performance and quietness of operation. I currently have what I think is a manual Jabsco model that seems to have had an electric motor added to perform the pumping action, operated by a push button wall switch. It operates ok, sometimes struggles to evacuate the bowl, and can be fairly noisy, most noticeable with company aboard during the night...
My understanding of this Elegance model is that for my purposes with raw water intake, I will have to install the toilet, new control panel/switch, plus wire and plumb a new water pump in line for water supply to toilet. My only uncertainty is powering the new pump. I do have 12v in the shower drain sump in bilge where the new water pump would go, can I tap into this line?