you can put 245's on a 9" wheel, thats what size the fronts are on my 18x9 saleens and it looks just fine, and if you go with a bf goodrich tire like the kdw's they run a lot wider than they are marketed at so it will look just fine
245s on a 9" rim is going to depend on the tire manufacturer. I have 245 Goodyear GS-D3s on a 9" rim and it looks too small. Either an 8" rim or 255" would look better.
i have 18x9" rims now, both front and rear. 255 on the front, 285 on the back. i use toyo t1-Rs and 255s on my 18x9" rims already looks small.
i want 245s on 17x8" rims for the front. 245/45/17 on 8" rims is stock, and that is the look i want for the front tires. i guess i can live with 255s on 17x9" if i have to though.
i want to go to 17x10.5" on the back to improve traction because the 408 is going to be an absolute torque monster. 135/35/17s are going to grip much better than the 285/35/18s i have now.