[Veedub]

I found a set I like, and did some research and noticed alot of you guys use wheels with 42et or higher, but I notice also most use 16's or bigger.I found a 15x7" rim with a 50et with 6" backspacing.Is there a reason you guys skip over the 15's and go bigger besides just because it fills up the wheel well?
Also would they both fit under the front and rear, because I did see some guys in the readers rides galleries running stock fenders with the wheels tucked in for a stockish look?
Again thanks alot guys.