What is the #1 missing product

[Green_Elite_Cab]

Those look like they could be kitbashed from an Athearn Gp40x. Is the length different than a standard Gp40-2? It looks like they have an extra 4 feet at the back of the long hood, I presume for a hep unit, but it definitely looks doable.

Not accurately. A Gp40X is actually MUCH shorter than these commuter locomotives, and the flared radiators are completely wrong (the radiators are too short and flare differently). An SD45 is almost a better starting point, but either way, its all madness. I haven't yet found anyone who has completed such a kit bash (though many get about halfway in and just don't seem to know what to do next). I suppose i could try it when i finish all the other projects i have, but I'm not confident in it. I mean, how would one even add those vents to those engine doors below the radiators?

besides, a good SD45 Starting point is not cheap. I'd love pointers on how to do this sort of thing, but its just above my current skill level.

I saw that pic of the CDOT loco and was thinking"Wait.....Thats a BL20GH!" Piece of crap. Always breaking down. They were suppose to replace the FL9's, but with all the problems CDOT and Metro North is having with them, the FL9 is still going strong.
But yeah..The cores were old GP40's. CDOT had a few, and traded them in to become BL20GH's. Bad move.

Thats not a BL20GH. Notice that this CDOT engine is actually attractive. a major spotting feature of the BL20GH is EXTREME UGLINESS . The unit pictured is indeed a "GP40-2H" or something along those lines. Its essentially a GP40PH-2 with just different ditch lights and fuel tanks.

Maybe its just me, but I could never see why anyone would model something you're not going to see on the layout... .... A lot of the newer Athearn's have this detail, and I tell you, with one of my trains rolling at track speed...I don't see it.

Its all in the photography, especially on the modern stuff. For example, just yesterday i saw a freight train go by, and it had all that break rigging clearly visible. Now, maybe if a train is running, you won't see all that, but if you take a track side photo of the model (much like many of mine), you can't get away without some of these details and claim to have something realistic. In my case, i just focus the work on my favorite models, I'm not to crazy about detailing everything. In the end, i think it depends. I have an Amtrak P42DC that when i first got it, it seemed fine, until i bought an Amtrak book, with good pictures of the P42DC, and i could see all the little air dryers, filters, and piping and such. enough of it is visible from the sides when you get down to it that it really makes a difference to have it.