I can't understand (sorry for being honest) how the tyres are difficult to find, as we supply over 40 variants in that size in the UK (and ROI) market
215/45-17 and 225/45-17 are close enough on the overall diameter to work, but you have to change 4 and be aware that you may have clearance issues as they are wider.. you'd need to check that, and ensure that the wheel size is ok.. Is it 6.5 x 17??
As far as I can tell, outside of the big cities, brand choices are limited for that particular size e.g my local Ford garage only has a set of Kumho tyres currently in that size and previously I got a set of Avon ZV5 from them. Also as a result of this, the prices tend to be more than the more common tyre sizes or they have to be specially ordered.
I'm not 100% sure of the wheel size. It might be 7x17?