one thing about runner length is that not only is it going be different lengths for NA or turbo but they both use the same general idea, longer lengths is going to be good for top end, shorter lengths are going to be good for bottom end power. note that if you have or are going to have a large turbo, shorter runner lengths are going to be your best bet for bottom to mid range power. however if you have a smaller turbo, 28rs/2871/maybe even a little larger turbos with smaller AR longer runner lenths are going to be your best bet for top peak power as smaller turbos are already going to fill in the bottom to mid range power so obviously having something that will optimize the top end would be for you.
do note that runner length is important and there really isnt a general all purpose runner length, so dont just order a intake wouldnt actually taking the time to find out what is going to best suit your needs, otherwise its just a waste of money.
just my .02