2 rabbits, even from the same litter, may not get along once they reach adulthood. Hormones play a big part, but even neutered males don't usually get along. You would have to separate them around 3 months old to prevent them from fighting, if they do start to fight it can be very difficult to bond them again.
If you want to best success rate for bonding, a spayed female and neutered male is the way to go. If you get them from a breeder, they do need to be separated no later than 3 months old to prevent breeding. Males can be neutered once their testicles drop, usually around 4-5 months old. Females can be done around 5-6 months.
I would not really recommend getting 2 at the same time anyway. I would get one, then get it spayed or neutered when it is old enough. You can then look into getting another one, preferably letting the one you have choose the mate. Get the 2nd rabbit fixed before you try bonding.
If you still want to get the 2 males, be prepared to separate them and the possibility of having to have 2 separate rabbits if they don't get along.
