I was wondering if anyone has run a 245/40/19 on the front instead of the OEM 255/40?

The reason I ask is that I am going to be putting the OE 285/35 rear tire size on an 11" wheel, which will give it a very slight stretched look, although the tire I'm looking at has a 11.8" section width on a 11" wheel....so it may not look stretched at all..I dunno. Anyway, I was thinking that a 245/40 on a 8.5" wheel might help match the rear sidewall visually. I was thinking a 255/40 might look a little bulgey when compared to a 285/35 on 11's? The 245/40 is only 1.19% shorter in diameter than the 255, and the section width is slightly less obviously.
Should I go for the 245/40 or stick with the 255/40?

Oh, and this set-up is for a M6

Any help would be greatly appreciated