At night i use a OSFM BBH, if you turn the frills on the leg inside the nappy they contain poo-spolsions really well. i think that these are $25 each, but cheaper if you bulk buy... you need a cover for these nappies.
Honestly they are a great nappy for everyday use and night use. I have other nappies that i also use, but if you are looking for something that both your boys can wear day and night i would go for these...
However there are loads more girls in the know that would better answer your questions...