Should have been 235/60/15 ? - irrespectively, American tyres are increasing difficult to source in 15" sizes. Partly because they don't meet EU emmision laws. The best you will do is BF Goodrich at hefty prices (if you are lucky) try North Hants Tyres ---------- or upgrade to 18's.
Call North Hants tyres and speak to James, tell him I sent you and he will go through options with you, they stock bf Goodrich and should sort you out straight away :-)