Have you decided what you are going to wean them on to?
There are lots of options but personally I give raw chicken or beef mince - minced myself from lean cuts so I can control the fat. The reason I do this is because it is a natural diet for them (raw meat)and if my bitch pinches it, then it kicks in her natural reaction to regurgitate semi-digested food for the pups.
For a second type of food I'll then go to a widely available puppy complete kibble - Beta Pup/Junior as that is easy for me and new owners to get ( not a great range of puppy food here in the Hebrides).
I also give raw vegetables as puppy chews, little sticks of cucumber to begin with and later onto carrot which is crunchier.
I'd be interested to know what you choose.

Sgurr