Powered Sewer Hoses and Sewer storage tanks

[cattfuu]

Who has experience with or information about powered sewer hoses and reduction of storage tanks due to the space requirements?
Considering replacing the standard 'scooting on knees' type sewer pipe with powered sewer hose on a 40' bus and wonder whether this will require a reduction of the black and gray water tanks to make space for the reel and hose. The bus has roof airs, but I'm sure it is crowded down there. Has anyone else made this modification? Don't want to loose tank space but sure would love pushing a button and have the hose shoot out of the bottom. Oh those aching knees.