Cages are cages, no matter how good, no matter how big. If you can dedicate a room or two or three, or even part of a large room to your guinea pigs, they will be happier than being in a cage!
Each album is a set of photos of a free range environment. You can also get some additional ideas for floor time from these photos, even if you must use a cage.
Joyce's Free Range Album Joyce had an entire large room (and patio) dedicated to her special piggies.
Dawnda's Cage to Free Range Album Dawnda has a few awesome photos in this album on her evolution from cage to free range. Some great ideas.
Lynx's Free Range Album Lynx has a huge 400 square foot space allocated to her pigsters. She also has a web page which talks about the history of their environment and explains the photos in detail.
Snaggletooth's Free Range Album They have some stairs and a stair landing in their free range environment--lots of exercise for these piggies.