Suntan
I can't recall how many pieces of diapers per pack, am at work now, can't check. But its the cheapest I can find and good and if they are on promotion only $10 per pack. But the cheap price only valids if you order directly from them. NTUC and other major supermarkets also sell but is about $2 more expensive.
Autrum
Yes, initially I also think is the difference between baby boys and baby girls. But my friends who had boys and girls all said this brand is good. So I tried, it holds urine very well, so even if you don't change the diaper for 6-7 hours, it doesn't leak and it remains dry.
For Nepia, I must change every 3 to 4 hours, it doesn't hold urine well