All bunnies are better off in pairs. Are you completely stuck on giant breeds? If not I would look at your local rescues for a neutered pair. giants do come up occasionally in rescues but are harder to find.
If you are going down the route of going to a breeder I would personally go for one & as they get towards neutering time start looking for a rescue buddy. You can get an all female or all male pair but you may have difficulty as they mature as they may start to fight & of course no-one is infallible when it comes to sexing so you might also get a nasty surprise.