Modeling the Tier 4 projects

I'm expecting to start a project of a new CN Tier4 locomotive..I notice that the new model are close to a AC4400,but,I have few thing to do to make it more prototype,need a higher angle on the back radiator,and add a box on the roof,near the back radiator,for the sides,the details are pretty close,but I'm seraching good pictures,I found some,but can't find all the angles..I found the left side,the right side,the front,but I'm keep seraching for picture from the roof and from the back,I have the decals for it,and i'm seraching to find back radiator pieces,I'm starting it from a Atthearn blue box AC4400

and there is the one I want to do
http://ewebcarpenters.com/beta/cro/REST ... KOENIG.jpg" onclick="window.open(this.href);return false;

i think it depends on on the roadname. I've seen some BNSF tier 4's that almost look like a regular es44, some csx's too. Thats the first i've seen with that large box at the end.