Suggestions please.... shopping wheels for PeterGreen

[petergreen]

The Beemer's doing alright; I've had the front wheels balanced to get rid of the shaky steering between 60-70mph, the interior light has been fixed and upgraded to include map lights and the leaky boot has had new rubber. One problem I have found is the price of tyres; They're a bizarre size (230/55/390) and they cost about £135 a pop!!! I've asked a BMW breaker to source me some imperial wheels for her to keep costs down.