my opinion is to stick with the prof recommender. the peer recommender might be a nice tangential reco, but there's no replacement for a well-written, high energy, and enthusiastic reco directly from a manager. if you feel, however, that such a reco will not be possible with your current manager, for whatever reason, than perhaps your partner reco is a nice substitute, as long as the content of her/his reco is STELLAR. you're coming off the beaten path by finding a non-manager reco, so it really needs to shine and standout. otherwise, it will appear as though you weren't able to obtain a more trad'l reco. i always say a good reco won't get you in, but a bad one will keep you out.
hope that's helpful,
Former Kellogg adcom member, offering a new approach to MBA Admissions Consulting.