As mentioned, both offset and wheel width will affect how much the wheel sticks out past the fender. A lower offset like 20 or 15 will stick out further. The wider the wheel, the more it will be. A higher offset like a 40 or 50 will suck the wheel inside the fender. You can compensate by going with a wider rim. An 8.5 in wide wheel with about a 30 to 35 offset will set pretty flush. A 9.5 in wide wheel with a 40 to 45 offset will also sit pretty flush. you made up the offset difference with wheel width. The concave spoke design will not affect this at all. It will still be based on offset and width. On a flush spoke design, a lower offset just means you will have a bigger lip on the wheel. For concave, the lower the offset, the more of a deeper dish look you will have.
I am not sure of the look you are after. I run 20x8.5 on a 35 offset wheel with 245/35 tire and sit just about flush.
like I said, when it comes to brake clearance, it about spoke design. The day we brought her home brand new from the dealership

Couldn't stand the look of the tiny brakes so put something on a little bit bigger. I figured I would be alright with 20 in wheels. Installed the brakes bled everything and tried to put the wheels back on. That was a rude awakening! So, had to go wheel shopping.
