We used to have guinea pigs. We had them for a few years but had to give them away when we moved from Ca to Ky. I was afraid that the long trip would be too stressful for them.
Mine were picky eaters too. They loved to be put down in the grass and they run around and play. You just have to keep a close eye on them or they disappear. Mine loved to sit on the shoulders while I walked around but if I stopped they would get mad a pee down my back. I still loved them.
You do have to bathe them regularly or they can get mites and skin disease. Keep the cage nice and clean this will help too. When they are happy they will make a purring or a quiet chirping noise. When they are upset or hurt that chirping can get very loud.
And yes they like lots of attention.