Aquariums are for fish not guinea pigs you should get a wire walled cage. Fresh air is good for your guinea pig and if your cage has wire walls it will help the air flow, plus your cage will be dryer and will smell better too.

While your walls should be wire it's best not to have wire for the floors your guinea pig can get his or her feet caught thus injuring your cavy.

Wood is not a good choice either, it absorbs odors and moisture from the guinea pigs waste, then germs would form harming your guinea pig. More common to cavy cages is plastic it's easier to clean. When you are looking at cages see if the cage bottom slides out, this makes it easier to clean.

In addition to an easy to clean floor you need to make sure the door size is acceptable. Not only will you be able to comfortably pick up your pet you it will help when you need to clean your cage.

Your guinea pig loves to run laps and this is so good for them so your hutch needs to be big enough to do this. Guinea pigs are social creatures you should get two of them instead of one if you do they need about 10 - 11 square feet at the minimum.

Occasionally a guinea pig needs a little place to hide itself they like a bit of privacy too, so you should provide them with a box to hide in when they feel it necessary. You can purchase a nice box for this purpose or use a container of your own.

To line the floor of your cage for comfort use paper with a top layer of bedding, do not use cedar chips they maybe suitable for other animals but not guinea pigs they have chemicals that can interfere with their breathing.

Shredded paper and timothy hay make a great combo for guinea pigs bedding they can nibble on the hay too, and it's good for their tummy too.