Is the ECE 4 - 6 drop too low?

[MisterE72]

Hi all,
I currently have a 3.5 - 5 drop (2.5 spindle 1" coil/5 rear coil) set up ready to install on my truck. I thinking about running 20x8.5 front wheels (255/40/20 tires) and 20x9.5 (315/35/20tires) rears. I'm not looking to get too aggressive with the off set. Do you all think that a ECE 4-6 drop would put the truck so low that I may have tire rubbing or turning issues. I have an oppertunity to sell what I have now, but i'm not sure if I should. I'm aiming for a stance like the one pictured here. Throw in a picture if you are doing something like what i'm aiming for and a little advice if you can. Thanks.