No. 1 myth - Offset does not determine brake clearance.
Disk type does or some people call it the X Factor.
Below is an example of standard, low and high disk rims.
Work Wheels normally denote this with O, R and A
Rays use A,B and C
SSR use Hi, Low, Standard
If you are buying a Jap wheel the specs car will normally give you this info.
Hope this clears things up Pete.