@mumofsupergirl I volunteer in animal rescue, and I'm sorry to say that nearly all the cages recommended by posters here are far too small and completely unsuitable. They are the sort of thing we have pets handed to us in, and we throw into skips so they can't be re-used. Also, nothing high with levels as they can fall off and injure themselves.
Bedding - Please also never use shavings or sawdust for the same reasons we wouldn't sleep in it, its an irritant and can cause respiratory issues. Something like Carefree, Kaytee or Megazorb is kinder.
Wheels - Throw away any wheels cages come with as they are never large enough. Wheels need to be 28cm minimum for a Syrian, and 21cm plus for a Dwarf so they don't suffer back injuries.
Hamsters may be small but they need a lot of space. The first cage you linked to The Hamster Heaven is ok, but the smallest size we will rehome in is 100cm i.e. The Savic Plaza www.petsathome.com/shop/en/pets/savic-plaza-hamster-and-rat-cage but check the bar spacing.
As @OldReliable says they need space to dig and run so ideally go for a tank, as they have no bars to escape from. You can pick these up as 2nd hand aquariums or the Ikea Detolf is only £70 and Kirsty's Tank Tops can make you lids if you're not DIY minded www.facebook.com/search/top?q=kirsty%27s%20tank%20tops
Google "Hamster in a Detolf" to see the possibilities and how much happier your Hamster will be with space, rather than stuffed in small plastic 60cm container/cage. It's so much better for you to interact and watch them displaying their natural instincts. I've attached an example.
Although Dwarf Hamsters can exist in groups, they tend to be temperamental and "can" fall out, which is why they are often singles. The same with Syrian Hamsters. They are the exception as all other rodents are highly social and must be kept in pairs or groups.
Always consider your local rescue as you will get much better advice than Pet Shops who are usually inexperienced. Good luck!