10 weeks and 7kg? My dog was 5kg at the same age - so I'm guessing yours is going to be BIG.
So I don't know any rules about age and what kind of bones. I think my vet recommended chicken wings and cutting them up if the dog hoovered them. Then again chicken wing also came back to haunt us. I think if I froze it first it would take her longer to eat it, and she'd chew bits off it instead of trying to swallow it whole as soon as she could - I swear she was a sea lion in a previous life.
Lamb necks was what she vomitted last time. What you have to watch out for is the hoovering. Could your dog hoover a lamb neck?
Not sure about buying bones from a pet store. It's nice they have helpful advice but - apart from dry dog food, I get everything I give to my dog from the same place I buy food. It's got to go in my fridge too so I don't want the different food handling standards in my kitchen.
However my family got into the most trouble with something called "chicken mince" for pets which was actually minced carcass - bones and all ie not suitable for cooking - we didn't know that and dog got very sick. And that was from a butcher. Bad butcher. He's gone now.
I don't tell butchers when I'm buying for the dog. Bones are for soup or osso bucco or roast. Stuff the dog, I love roast lamb neck bones, she's getting none. Mince is for bolognese or hamburgers. Right? And if I get 1.2 kg instead of 1kg - then that .2 is for bolognese. And I don't have to feel worried it's not good enough for me to eat.
Actually a lot of people at dog park ask me from time to time if I feed my dog left overs and I say - mostly no - because I never have any left overs - I eat it all. Sometimes there is the chewy bit from a steak and I chop that up for treats. And that's as close as she gets.