Hello
A 40 gallon tank is still a great size! Yes the Alexander is a lovely cage and there aren't many big cages available in the Us (only 2 or 3 I know of). It is made by a German company (the only reason we get these big cages in the Uk is because the Germans and Belgians make them!) so they only ship within Europe. There are a couple of Savic cages available on Amazon.com but they're not as big as the Alexander and smaller than your 40 gallon tank.
It would be possible for your grandparents to buy it and then ship it to the US - the box they come in is pretty big, and it could get damaged in transit too - sometimes people have one arrive with part of the base broken off. The base is not as thick and sturdy as it could be. It's absolutely fine but there have been a number of cases of a base damaged in transit. Sometimes it's repairable. But European owners can get the cage replaced free if that happens and you wouldn't be able to.
Have you seen the detolf?! You can get that in the US - it's a glass cabinet from Ikea you tip on its side and leave the door off - needs two lids making out of wood and mesh and costs about $60. It looks very nice sitting on top of Kallax storage units, which is also practical for storage.
But I'm guessing it's a cage you like. There is a very good cage available in the Us (hard to find) called the Marchioro Goran. It's not quite as big as the Alexander and a bit less long than your current tank, but it is also deeper than your current tank, so still a good size and a good height without being too tall - it will fit a 12" wheel and has a lovely big front opening door so it's great for taking things in and out of the cage and for interacting with your hamster. There is also a stand available for it I think. It's 32.25" long by 20" deep by 14.25" high.
I bookmarked this link for it because it's the cheapest price I believe. It's the 82cm version at $107 dollars. It's a great size cage for a Syrian hamster and comes with a lovely big rat sized tube (rat sized toys and tubes are a good size for Syrian hamsters) and 1cm or half inch bar spacing, which is fine.
Marchioro Products Marchioro Goran Rat Cage Small Pet Cages
The Alexander cage is great, but the advantage you have with a tank is you can have really deep substrate so your hamster can dig tunnels. But if you've set your heart on a cage I can understand, and the ventilation is very good in a cage.
There is also this cage available in the US - it's 39" long by 21" deep (it's a 100cm cage like the Alexander) but it is very tall and needs a fully level putting in ideally. In the Uk it's called the Mamble cage. In the US it's called the Ferret Kit cage.
Although it's bigger than the Marchioro Goran, the access isn't quite so easy with two smaller front doors and it can be a fiddle to fit together. Plus it really does need a full level with being so tall or your hamster could injure themselves falling from the top - so it would mean a bit of diy. Whereas the Goran is set up and ready to go.
https://www.walmart.com/ip/A-E-Cage-...bitat/36236422
Other alternatives are: A bin cage made from an Iris Christmas tree bin - they are really large. But a detolf may be nicer
Or a diy cage (if you don't mind diy). Or a 50 gallong tank
Hope this helps! We are lucky to have a good choice of cages in the Uk, but on the other hand glass tanks are too expensive here (outrageously expensive!) And there are plenty of people upgrading from a 100cm cage like the Alexander - to a detolf
Some examples of detolf set ups
https://www.google.co.uk/search?q=Ha...48DyMQ_AUIBigB