I have had these types aquanano tanks before.
These are actually pretty good little tanks it has to be said.
Removing the built in filter at the back of the tank IS possible but not that simple I don’t think. Be fairly difficult to remove without either damaging the filter compartments or scratching the tank glass somewhere.
But the filter itself on those aquanano tanks are good things, does exactly what it says on the tin really and pretty reliable, never had an issue with any of my aquanano tanks and filter.
Lighting unit on those is a bit meh and I tended to upgrade lights on those tanks anyway.
Bonus is you would not need an external filter and the heater is in the back filter compartment as well so that saves space and more visually appealing inside tank, imho.
But if side of tank viewing is high on list then perhaps would leave this one and go for one without an internal filter.
Some tanks with internal filters, like Juwel Rio or 180 which I have, these internal filters can be removed without too much trouble, bit fiddly and a bit of work to remove the blobs of aquarium sealant that holds filter to glass but certainly doable.
Or as others have mentioned, there are good aquariums second hand deals to be had.
I find that lotts of second hand tanks tend to be dirty and have hard water marks on glass, bit of work to remove those and throughly clean the tank to satisfaction.
Entirely depends on how you feel about that and what your budget is etc etc