As far as one-size pockets go, I've had the best luck with Tiny Tush. Very durable and fit well.
The issue with many one-size diapers in my opinion is that they don't fit a newborn that well, and sometimes don't fit a bigger toddler, so some people end up needing 3 sizes anyway. A nice option, then, might be Thirsties new Duo Diapers. I like the covers, and just got my diapers in, and will be trying them in the next couple days. The size 1 goes nb to 18 lbs (more like 16 lbs for us) and size 2 goes 18 lbs (15 for us) to 40 lbs.
The truth is I loooooove prefolds for the nb stage. They are so easy, low maintenance. You can fold to fit however you need and they keep messes in really well. Now that my nb is 4.5 mo and very wiggly, I now prefer fitteds or pocket diapers. In an ideal world, I would use nb, then infant prefolds for my babe, then when they outgrow the infant pfs (15 lbs for us), switch to fitteds or pockets.
hth!