You need more than one! The best place to get guinea pigs is a local rescue shelter. Try the Blue Cross, Wood Green, or RSPCA. Often there are small local rescues that specialize in guinea pigs so google. If you are adding a guinea pig to an existing piggy or to a colony, the rescue may be able to help with the introduction. They can also find you a bonded pair or a bonded group and advise on housing and feeding. Guinea pigs hate a change of routine so it will be important to give the same diet etc when you first take your guinea pigs home and make changes slowly.
If the guinea pigs are for a child, adopting rescue guinea pigs will teach your child compassion. Adopting rescue animals is an unselfish act that a child can do. Many children take the act of rescuing very seriously. They cannot save the world but they can save two little guinea pigs. It also teaches them that animals are not just commodities to be bought and sold: they are living sentient creatures.
Don’t buy from a pet shop – it just encourages them to sell living animals and pet shop guinea pigs may have diseases (Rosenthal 2004). If you don’t want to get a rescue animals, then find a local breeder by googling. Think twice before buying a satin guinea pig. Many of them suffer from a genetic disorder which may mean a painful and early death (Jordan et al., 2009). Read about it here. Also think twice before getting a long haired guinea pig. You will need to groom them.
Jordan, J., Brunnberg, L., Ewringmann, A. & Muller, K., (20o9) ‘Clinical, radiological and laboratory investigation of osteodystrophia fibrosa in guinea pigs (Cavia porcellus) of the satin breed.,’ Kleintierpraxis, 54, 5-13. Abstract.
Rosenthal, K. L., (2005), ‘Small mammals in the pet store,’ Proceeding of the NAVC North American Veterinary Conference, 1374-1375.