Please adopt if you can. Make sure you find a vet that treats exotics. And remember, guinea pigs get bored so you need to give them lots of attention and floor time. Kids cannot really handle cage duties and extras until they are about 8 years old, so an adult will need to take care of them. Please look at the guinea pig application for Small Angels Rescue near Mount Airy to get an idea about taking care of guinea pigs. It is somewhat instructional, but that's because they want people to understand what they are getting into.
http://www.smallangelsrescue.org/
I just had to put one to sleep who was nearly 8 and haddeveloped tumors. He slowly lost weight from the cancer, but did keep eating, squeaking and enjoying life. I had to supplement him with a tablespoon of mashed pellets every day for 8 months and give him butt baths about once a week since his poops got a little soft. Pigs can live a long time. Kids get bored, you get bored and they end up in shelters at age 3 when people want baby piggies.
Then again, you may discover you are a pig family because they just are so cuddly and affectionate when tamed! GL!