hmmmm; Another Yazgood! I would imagine permanent service would be a better sale, as there are probably some high $$$ needs that would 'rent' fairly $$$.
anyway, i suppose you now need to separate permanent from temp. Is the service close enough to all served ( or heaviest loads) to simply have a receptacle bank ?
if your present does 410-57(b)(2) apply? Gotta job every gig they do?