First of all, a full size 185/55R16 fits perfectly in the spare wheel well, I have one in there right now with rags filling the additional space!
The Rover 25 space saver can be used (125/80R15).
The other 2 tyre sizes on full size wheels are 175/65R15 or 185/55R16.
The 14" wheels are from a GD Jazz.
A word of advise, do not play around with different wheel sizes, you can end up in all sorts of bother with ditches and insurance companies.
The centre hole of the wheel must be 56mm, otherwise it is not correct. Mini one wheels will also fit.