Go the wider if you can, improves overall stance and handling and traction up back.
Missed your question, not sure why you wanted smaller up front or what worried about there. I personally prefer the offset look since the rear fenders are larger openings, and the same all round can make the front look larger, or the rear smaller, I like them to match. The front track is also wider than the rears so if you fill the fronts, the rears are still inside the lip with same sizes.
Not sure if that's what you meant. Anyway, if that's what you mean then only step down to the same size but perhaps 245 or even 235 but keep an eye on the diameter, have to check when you may need a 65 series for same diameter of rears. Having different tyres from front to rear also limits your rotating them, although that's more of a daily driver thing.
