The strap can be adjusted in size. It does take a bit of fiddling to get it comfortable and stable, but once you do, it should be good for all future use. Assuming, of course, that only one person is using it. If it's too tight, then loosen the strap going around the back. If it's hanging down painfully, adjust the top strap to get things snug enough that the weight is distributed evenly.
I bought a BOBOVR M2 from AliExpress.
O.o You are braver then I am. I wont touch AliExpress with a 100 foot pole, let alone any payment information.
All things being equil though, for the OP I'd recommend against even considering Oculus's Elite strap. From everything I've heard, it breaks far too easily. You'd be better off adjusting the size of the default strap and maybe buying pads that can be attached to it.