I use a combo of things on DS2 depending on my mood, what we are doing, where we are going. Mostly, I am using pockets at this point with some fitteds thrown in. And I got a Flip Daypack a month ago or so. I really like it for DS2 as he is 18 months but I wouldn't recommend it for a newborn. The inserts can move and bunch plus they would never contain newborn poop - it would be all over the cover. I prefer fitteds and covers for newborns and young infants - I have only used Thirsties, Motherease, and now the Flip covers, which could be used over a fitted or prefold as well.
Hope I didn't confuse you here - I just wanted to steer you away from the Flip for the first few months since I think you will have a better cd experience with something else.
As for sprayers, I don't have one. I am a dunk and swish girl but that type of thing doesn't bother me. And our toilet has never gotten too full of junk to flush.
Mom to Two Wild and Crazy Boys and One Sweet Baby Girl