You need to find qualified rabbit specialist of a qualified exotic vet, not sure about Italy but over here, despite rabbits being the third most popular vet, normal vets dont learn hardly anything about them, as they are classed as exotic animals as they can be very complex. Hopefully the one coming to your practice should be able to sex them, but is there a way you can see them on a more regular basis?
Girls dont usually fight so young, how odd. But whether they are boys or girls, you wont really be able to tell whether they will bond again until after they are neutered, so keep them apart for now. Hopefully their fighting wasnt bad enough to hurt future bonding.
Out of interest, why on earth did you get your rabbits from a breeder in England and then ship them over to Italy? Surely you can get rabbits in Italy?