42mm or 50mm offset

[chase580]

I'm think of purchasing some Centerline RPMs for a real good price. They are 17x7 and weights ~14lbs. The two offsets that they offer are 42mm and 50mm; here is my question... Which offset is better to stuff them under stock size fenders?

The front is going to be narrowed 2 inches per side (along with cb dropped spindles and disc brakes) and the rear is going to remain stock (other than disc brakes). The car is a '62 and it will be lowered so the wheels will fill the arches without any gaps. I'll figure out what spacers I need later but at this point in time I have no clue because the only aftermarket wheels I've purchased for a bug are the typical BRMS and Empi relplicas. Any help or advise would be greatly appreciated.

Thanks,
Chase