Have a look on my mate's website www.twentytenengineering.co.uk and in the gallery there are a couple of pics of his old bobtails with P38 alloys on and a 2 door with predators. Also if you search for twentytenengineering on YouTube there are some clips with a 4 door with predators on.
I think they can look quite good on the right car, but its risky! My brother in law tried the predators on his softdash and it looked very wrong!
some years ago i had 18" on a 91 classic,i purcased special wheel adaptors think they was 200 quid ish and in all honesty i think it destroyed the ride,much better left original imo