I had bonds 00 singlets and Kmart brand 000 singlets and used them from the beginning. They were a bit big but came down over the nappy and prevented ride up of the singlet. I am still using them now for my 8.5kg DS, they are a bit smaller however. Ds was 3610g born (7lb15). I also had a couple of 0000 bodysuits from best and less. If you wait till they ar eon special you can pick them up for a few dollars. I also like th best and less all in one suits. I picked them up for $5 but they are normally only $7.99 I think. I also had some 0000 cotton on kids long sleeve bodysuits and pants. IT was pretty hot still when DS was born so he wore singlets and a wrap a lot.