my suggestions are:
You could get a bunch of velcro covers and prefolds and tri fold them into the covers. You would so thru more covers because they are trifolded but it seems it would still be cheaper then pockets and AIOS since you change them everytime too. Green mountain diapers has some pics of newborn covers with prefolds trifolded.
http://www.greenmountaindiapers.com/prefolds.htm#fold
For pockets:
bum genius one size they have velcro and a 1 year warrenty on the velcro. So before the 1 yr mark you can send them in and get the velcro replaced if they are not working well anymore.
*My dd was 9lbs 3oz at birth so she started wearing them at 2weeks after her cord fell off and at 32lbs and 21mos she is still wearing them
For AIO's:
Bum genius org one size- They are discontinuing the velcro so you can find them on sale for under $20.00. I am not sure if they have teh ame warrenty on them since they are being clearenced out .(but I think they can send new velcro if needed).
I am not sure on a good velcro fitted but I am sure there are some. I use clover fitteds that are great but have snaps. THey do have a one size tie fitted called the shamrock that looks kinda cool but I am not sure how your dp would like ties. (THey have a liftime warrenty on their diapers)
http://preciousdignity.myshopify.com...ze-wrap-around
ALso I forgot to answer your other questions:
What are the best for the nb phase? Infant through potty?
I think OS pockts and AIOs are great through all stages personally and if you use prefolds and covers the small prefolds can be used as doublers later or inserts for pocket diapers.
Absorbency?
you can add more absorbancy as needed with prefolds and covers and pockets with AIO's its a bit harder unless they have a pocket opening.
Do you add soakers/prefolds to them as the child grows and pees more?
I never add anything to my prefolds and covers I just move up a size( I use green mountain diaper prefolds) but with pockets I sometimes add inserts to them.
HTH
