I think finding a good person is more important than modalities - and is often the trickiest part of the process. Which is (ironically) especially difficult for the depressed.
Yes it is. I've met many people before finding someone that I can trust a bit.
Carl Rogers was an interesting guy and he had a scientific approach (as I like understand how things work). It's a model that fit well to my mind.
https://www.youtube.com/watch?v=iMi7uY83z-U
I guess all models have nearly the same success rate.