Rabbits... ALL RABBITS... can be friendly young and as adults. Your question poses several interesting points.
I have a rabbit farm/ amateur rescue with over 200 rabbits (350 with Easter coming up) so I have quite a lot of experience with this. Wish I had all good news, but here is my two cents worth...
I have found any rabbit, when given enough positive attention, will be a good rabbit. Friendly disposition comes from the amount of attention they get almost daily. A friendly rabbit who is ignored for a month, only getting food and water, no petting, will withdraw. Within 3 months, it will be evasive and possibly hostile. A rabbit who is abused in some way, constantly scared, like with barking dogs they think will eat them, will become hostile.
Breed has a lot to do with adult temperament. Look up lop rabbits and their calm, snuggly, disposition. This is from years of breeding for just that personality. Flemish Giants are reportedly like giant lap dogs, always wanting attention and super friendly. I have one Flemish doe that will tear the door off her cage if she doesn't get petted every time you walk by.
I also have a flemish giant doe that will run away, box, or even try to bite if you get close enough to her. She was not handled enough growing up and will likely never be a true snuggly bunny.
I have Netherland Dwarf bunnies the same way. Some great, some evasive. It all comes down to how they are treated and how often they get that positive reinforcement.
I would agree with other on the age issue. Under 6 weeks, you are pushing your luck as so many things can go wrong just int he transition from their mother, to the store, to your home. Bunnies CAN be weaned at 4 weeks, but it is better to let them wait until at least 6 weeks.
I hope this wasn't too drawn out and I hope you find that perfect bunny to add to your family.