This is the hard part! Here are a few descriptions and comparisons of each breed to help you decide:
Netherland Dwarf
Netherland Dwarfs are one of the smallest breeds of rabbits and weigh 2-3 pounds when full grown. Netherland Dwarfs tend to be a little more reserved and well mannered. They are WAY more gentle, MUCH smaller, and more FRAGILE than other rabbit breeds. These little guys truly appreciate time with you (but don't demand it). They also don't mind just sitting back and hanging out with you. We think they would be great companions for an older more mature child, specially because of their delicate frames.
Holland Lop
These lovable bunnies are the smallest of the lop-eared rabbit breeds. With their compact size, adorable features, and sweet temperament, it's no surprise the Holland Lop has become one of the most popular rabbit breeds in the world today. In addition, the playful and enduring character of the Holland Lop helps make it an ideal family pet and show companion.
Holland Lops tend to have an amazing and outgoing personality. They are very docile, affectionate & make great pets for families with young children. Hollands generally tolerate being handled very well if they are held daily. Hollands are the smallest of the lop breeds and the only dwarf lop breed. They are 3 - 4 pounds fully grown and can easily be trained to use a litter box making them excellent indoor pets. FUN FACT: when breeding Holland Lops, you sometimes have "fuzzy lops" pop up in litters. This is because during the development of the breed, angoras were used to introduce new coat patterns. So if the genetics work out, a wooly lop appears. This breed went on to become the American Fuzzy Lop(AFL).