Wally,
I maybe being thick here but if you want to clear the arms would a low et not be better, even a - et so more of the dish is on the outside and less on the inner of the wheel.. Not that mechanicly minded but know my wheels
so maybe completey wrong..
Anyway i am waiting a set of lightweight Revolutions rfx (5x130) in 16x8 not 15's if anygood the guy i am getting them off said they are 40ish et but can confirm next week
On the other hand i have these BBS 15x8 et-20 about 90mm of backspace on the inside and 100mm on the outerdish
Hope i can be of some help.. if you can get away with 16's what about some getting some cheapo design 90 16x8 et52 or 16" cup1 in 16x8