I don't know if this is too late but I stayed at Crystal Divers in Sanur last summer and was happy with it. The rooms were really cheap and good, the dives were great. I did not see mola mola but loads of mantas and also went to the Liberty wreck.
The groups were small and the guides nice and pleasant. They weren't the "in your face" type of guides you felt more as part of a diving group.
The only downside was that they only rent shorties and I think that is too Cold for Nusa Penida so bring a full 3mm.
I did some videos with a handheld point and shoot camera so not the best but gives an idea of the diving.
Nuda Penida: Nusa Penida - YouTube
Tulamben: Tulamben - YouTube
The groups were small and the guides nice and pleasant. They weren't the "in your face" type of guides you felt more as part of a diving group.
The only downside was that they only rent shorties and I think that is too Cold for Nusa Penida so bring a full 3mm.
I did some videos with a handheld point and shoot camera so not the best but gives an idea of the diving.
Nuda Penida: Nusa Penida - YouTube
Tulamben: Tulamben - YouTube