I've got 18x6 and 16x5 on mine with excelsior tyres. I reckon using 18s instead of 16s doesn't make the front rim look bigger than the rear with that tyre choice.
Glad to see one of you clowns finally gave the guy an answer. I've been considering a set of them myself.
How did you balance them ? Only on the insid , with selfadheasing weights ? How much did you need to balance them ?