All Habitrails are unsuitable I would say, especially for syrians. Not just size (though that is a huge problem for a number of reasons: not enough toys can fit, a big enough wheel can't fit, no continuous running space) but because of ventilation & heat regulation, unsuitable in appealing to a hamster's wall-hugging instincts, the list goes on...
A bin cage is a great way to go for your ham!
You will be looking for something about 80x50cm in base size for a bin, that provides running space and make sure the bin is high enough for at least an 8" wheel to fit. We'd love to see pics of it (or a possible commercial cage that you opt for) soon!
Oh and welcome to HC!
