I would have thought it would have came with STI seats as well !!! strange but hay I could be wrong.
As long as you enjoy the car then that's the main thing Rab.
sorry to hear the bad news mate I hope you don't have to get rid of the car, fingers crossed that is the last bit of money you will have to spend on the car in a good while.
not sure what garage you use mate or where you are based might be worth giving Greersport a call they will be able to either give you a price, they know scooby's inside out.