Even if they are small rodents, as family members, your hamsters have rights to live in a cozy place. Unless relaxing environment, you cannot be your hamsters' real friend.
The best environment for hamsters are of course the environment similar to their home town. But it is almost impossible, unless your house is a Zoo (Hamsters are living in tunnels under the ground, so you need to have very wide backyard with good soil to establish the same environment).
It also keeps hamsters warmer than cages, that is another strong point. You may think tank won't provide good air circulation. The fact is, it won't be a problem. As long as the top part of your tank is wide open, it won't be a problem.
There are quite hot discussion if we should provide hamsters a hideout in the aquarium (or cage) or not. If you place hideout in your tank, they will be delighted for sure. But it may create a sanitation problem, some Vets are advising not to provide a hideout in your cage for hamsters.
cage and hideout regular basis (say weekly). Wooden box would be nice for hamsters, you can check your local potshot to find the box nest for small birds. The picture is special wooden cage for hamsters made by Japanese vender, Sanko. If you have a tool, you can make similar box.
Long long time ago, hamsters' bedding is shredded news paper. But now, you can purchase nicer materials at your local pet shop.
So far, those materials are recommended as safe materials for hamsters bedding at JHFA mailing list in Japan:
Recently, bedding materials made with corn cobs are seen at pet stores. Those may be ideal too.
Hamsters like exercises. Wild hamsters sometimes migrate more than 10 Km per night, small cage may cause hamsters frustrated.
may cause injure or your hamsters when they slip from the narrow ladder. With plastic wheels, you don't need to worry about such accidents.
Other than the wheel, it is ideal to have a hamsters' ball. This is a hollow plastic ball, you can release your hamster in the ball. If you release your hamsters in your living room, they may vanished or get hurt, which are pretty thrilling experience. However, if you release your hamster in the ball, you can avoid those tragic accidents.
It is said the best Temperature range for hamsters is 5 Celsius to 25 Celsius (41 Fahrenheit to 77 Fahrenheit). Lower temperature may force your hamsters to hibernate (which is very dangerous for pet hamsters, that may put your hamsters rest in piece), higher temperature will exhaust your hamsters pretty badly. So you need to control the temperature of your hamsters' tank.
The left is a heater for reptiles, but you can use for hamsters too. Please check your local pet shop. You may find ceramic heaters for reptiles, those might be a clever purchase for your hamsters.
Other than temperature, water supply is also critical. Even though original place of the hamsters is desert, they need water. Without water, they will die. Especially if you feed your hamsters with dry pellet, water bottle is essential.
The picture is water bottles from Lixit California, USA. But you can choose whatever water bottles you like. Water bottle is a water bottle anyway.
Some hamsters will learn the toilet manner. If your hamsters do their job at the same location, your cleaning work get much easier. Also it helps keep the environment clean. Your hamsters may not make it, but it is worth to try to make litter box in your tank. The pictures are litter boxes for hamsters. (upper left is "Hi-corner litter pan" by Super pet, below is "Hamsters' toilet" from Marukan, Japan.)
By the way, for litter sand, you should avoid clumping sand for cats. It may clump in hamsters cheek and create a problem. There is no article if it is true or not, but the best way is away from any potential risks.