Are the Durango and Silverton passenger cars available separately or only in the set?
You can buy them individually on ebay.
I have looked into this also. I think it's better to just buy the whole set for a little over $100 and part out or find another use for what you don't need than to spend almost as much on the individual cars.
B-mann is selling some of their rolling stock individually in plastic bags with a cardboard hanger. They are calling it either RERAILED or RERAILERS, I forget which. I have seen these at shows and in some hobby stores. There is one Annapolis Area hobby store that sells many Bachpersonn products that has quite a stock of these things. There is another major FeePay seller of Bachmann, but I do not know if he has any of the above. Both of these sellers have pretty good prices.
I found the Durango and Silverton coach in one of the packages, so I bought it. I have yet to see the combine, but I imagine that it is out there. Standard gauge Durango and Silverton is a bit odd, but considering that Con-Cor offered the Gallopping Goose in standard gauge, and, I bought one.............
I will put mine behind and Athearn and MDC 2-8-0s lettered for the Rio Grande. I have two MDC bumblebee 2-8-0s and one from Athearn in black. I have, also, two bumblebee 2-6-0s from Athearn. I guess that I could buy another Athearn or MDC 2-8-0 and letter it either for the Durangon and Silverton or Cumbres and Toltec.
The B-mann set comes with a USRA 0-6-0. Swap out the stock tender for a SPECTRUM and I guess that you will be allright, although the 2-8-0s might be closer to "prototypical", or as protoypical as you could get with standard gauge.
For more information on the tender swap, take a peak at Spookshow's website. There is a tutorial on how to do it. The B-mann USRA 0-6-0 with the SPECTRUM tender is a very good locomotive. The increase in pulling power and improvement in performance is impressive.
I had the same issue so i bought the sed and dcc'ed the engine. Then i sold the track and power transformer as a n scale starter track pack at my local club.