I've had lots of pets - gerbils, hamsters, mice, rats, bunnies... it wasnt until recently that we did the guinea pig thing - OMG - they are WONDERFUL!!
we cant have dogs and cats due to allergies... (ds, not dd) So we were on petfinder.org and "rescued" our guinea pig - we have 2 cages side by side - 2 guineas -
they are the short hair cavies, the longer hair needs more time, and grooming, so for dd we got the short haired guinea pig... she cleans the cages at least once a week - if it smells, it gets cleaned, the guineas dont smell unless they have to be in their smelly cage!!
They are totally interactive, and loving!! DD hasnt been biten, nipped at once with the one guinea... but she carries them everywhere - when we first got the guinea the owner reccommended a "sleeping bag" just sew on 3 sides, and you can carry the guineas... but its so cute to hear them "purr" or wheek, or beg... just too sweet - they are the best pets we've had!!
Also, we did lose one to the rainbow bridge, so do be prepared for that time as well - dd had helped a classmate through the loss of a dog, so she was prepared with the poem Rainbow Bridge, as well as the book "The tenth good thing about Barney" and "Fall of Freddie the Leaf"
so go for it!!