Another unpopular post, please do not do this. Going from 2 dogs to 8 dogs is a huge jump, and six of those dogs being littermates. There is no way possible that you and your husband can give as much individual attention and training to these puppies than if you sell, or give away 4 or 5 of them.
The puppies being the same age, and the same power are not going to have trouble now when they are 4 months old. But they can have some serious troubles down the line.
It is really a bad idea for the dogs. I am against spaying and neutering, but if you are concerned with people breeding them, do a pediatric alter before homing them. They are old enough at this point to do this.
Allowing six puppies to reach adulthood in the same home, is something that I wouldn't try.
It will not be fun, if the dogs start fighting. Really. Then it will be constant management.
Are they all house trained? If you still need to get that feat accomplished, six at once, that has to be fun.
8 very young dogs all at once is a daunting job. Right now they are still very cute and placeable. Yes they will be adorable as they grow too, but right now is the best time for them to adjust to a new home. Keeping them as a litter for another 2-3 months will create issues.
Please reconsider this.
Jenna, RN CGC & Babs, CD RA CGC HIC
Heidi, RA CGC
SG3 Odessa, SchH1, Kkl1, AD
Ninja, RN CGC & Milla, RN CGC
Joy, Star Puppy, RN CGC
Dolly CGC & Bear CGC