If you do get more than one, make sure you have the space/equipment to separate them if necessary. Even if they get on well now, there's no guarantee they always will.
Males do better when kept alone. Just about any number of females can be kept together well although without the presence of a male one may become the more dominant in the group. Dominate females are rarely ever as aggressive as a male and will generally cause no injury to other females.
I think that 1.2 (one male.two females) is the absolute minimum group ratio. If keeping this ratio a very large enclosure is needed with multiple barriers, resting areas. A better ratio would be 1.3 or 1.4.
A male/female pair kept together is rarely ever a good idea.