Male bunnies OK together??

Hi, I just brought home two little bunnies (8 weeks old, part giant, and not siblings). I'd heard that rabbits get really lonely by themselves, so wanted a companion. But am now wondering if the breeder was correct in telling me that any gender pairing would work and make them just as happy as any other (assuming that they get fixed at the right time)

I had done some research saying that male female was the easiest, but male male was also ok, but now am finding other sites that say that two males together should be avoided, and that one could be killed...

The breeder had several of both sexes available, so not sure why she would say it didn't matter if it did... One is mounting the other a bit and clearly more dominant, but for the most part they seem to get on well.

So I was hoping someone could give their opinion on the following:

1. Are two males usually ok, or should I return one of them and look for a fixed female later on?
2. If males should be ok together, can they also be kept together before they get fixed?
3. If they've been fixed, are they still likely to fight? Should I keep them in separate cages just in case, only bringing them out for exercise when we're around? I had hoped to house them together in an x-pen...

Thanks!