If I loose on a bid, i'll contact the seller and ask if he or she has another one and they usually sell me another of the same item for the same price that was won with or i'd pay a little more for it, but it depends on the seller if it's a retailer.
I use Kadee #58, 158, and 118's on my cars, but I have begun to use the Sergent type-F's on all of my locomotives, since the the Sergent type-F's don't couple properly with any other brands of couplers.
I bought a Paasche set for $112 at the LHS, it's a single action airbrush with a kit of an extra bottle, hose, extra needle, and a tool, I like mines and it does a great job.
I also bought a Parker regulator with an air/water separator because I use a 30 gal air compressor.
Sergent engineering.com
It's four couplers per pack, I highly recommend one to follow the break in instructions for the couplers to function correctly, all one needs is a pencil for the break in.
The coupler does make it look better and yes, the ditch lights are way too big,, the ditch lights on the Athearn Genesis ditch lights on the SD75's looks a whole lot better.