you're asking a lot of any trailer.
hybrids with quad bunk haven't been made for years, since the 3 bunk bunk end trailers came out. when you add 6 in the bunk ends, 2 in the dinette and 2 in the sofa bed, you have sleeping for 10.
not many traditional TTs will have that capability.
to expect a lot of storage in a trailer that sleeps 8-10, is not realistic. somethings got to give in order to having sleeping for that many humans, so storage space gets tossed.
many with that size of family, have the older kids sleep in tents.
finding a trailer that you can carry 8 bikes will be problematic also.
i would never carry that many bikes on the back of an ultralight trailer. i don't know of any bike rack that could handle that many, mounted to a trailer.