Sarah, I can only support what Mary has written - get an FX One.
If this is the more popular boat, then go for it.
As most people in this forum are from the US they are more knowledgeable about the Inter 17, which is not so popular outside the US. Also as the FX One is still pretty new in the US, not so many know about that boat.
Both boats are reliable and of reasonable quality. I like the rudder system of the FX One better as well as the rudder performance, but again subjective.

You may want to consider as well, if you have sufficient access to spare parts. If there are more Hobies around, it is obvious that you have better access to spare parts wiht the Hobies.
So let´s see you with your boat soon.

Fritz