That sounds lovely
A very lucky dwarf hamster! The hamster heaven used to be considered perfect for a dwarf hamster - and some people still use them. A 100cm cage is recommended now, if it's not too tall, as they're very active.
The other thing is dwarf hamsters love to dig so the more bedding you can give the better. At least 6" but the more the better.
It can be expensive to buy a new cage, but these are popular options:
The Pets at Home Habitat 3 is an inexpensive option and only £44 - it's in the January sale at the moment - it's usually £55. It doesn't have a big front door like the hamster heaven but it does come with a shelf. And smaller doors on the side and top. It comes in pink, blue or grey. You could have a deep bedding end by putting cardboard inside the bars.
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There is also the the tank style plastic home 3 at £50 which also comes with a shelf and large top access only. You could have one end with deeper bedding. It's a bit lower though so restricts how you set it up. Dwarf hamsters need lots of clutter - tunnels and hides etc - at floor level. Although cardboard ones are fine!
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The 100cm Grosvenor cage is also popular for dwarf hamsters as it's about the same height as the hamster heaven, so not to tall - it has a large opening top roof and no front door. That's about £70 and comes with a shelf. You could have deep bedding at one end in that by putting cardboard inside the bars at one end. Amazon sell it as well.
Rat Hammocks, Igloos and Cages, Rabbit Cages and Runs, Chinchilla Cages, Hamster Cages and accessories, Dog Chews, Dog Toys.
littlepetwarehouse.co.uk
If you do decide to use the hamster heaven, then you'd need to block off the tubes and penthouse and use it as a straight cage - dwarfs aren't good at climbing tunnels and would probably try and nest in the tubes as well and the penthouse wouldn't work.
The wheel should be fine
However it will restrict how much bedding you can fit in in the wheel area so in that cage it would be better to have a 9" wheel.
If it's from a rescue, you'll probably find they insist on a 100cm cage.