https://ogrforum.com/...0#157829273742601300
What is the Sunset/3rd rail model? Is Sunset a brand? I believe one streamline cars are articulated. I only run heavyweight cars for passenger service.
Sunset Models Limited is the master company that is sold under the brand name of 3rd Rail. You can find them at www.3rdrail.com. The company also offers scale passenger cars under the brand name of Golden Gate Depot. The company has been in business for over 47 years and started producing imported brass locomotives and cars for the two rail market. 3 rail models started being offered in the late 1990's.
Currently the company is still a small operation and offers the highest quality 3 rail items available on the market. Yes, they come at a bit of a premium but for a discriminating modeler they offer an alternative to the mass produced MTH / Lionel items that tend to dominate the 3 rail market.
While not currently in production, Golden Gate Depot offered wonderfully detailed plastic 20" scale length heavyweight cars with coaches based on the PRR P70 prototype in both the 1930's appearance with ice-air conditioning and the slightly later modernized appearance with the balloon roof and larger windows. They also offered a baggage, baggage mail, RPO, diner, 8-1-2 Pullman Standard Sleepers, 12-1 Pullman Standard Sleepers, and a Pullman Standard 80' observation. They can be found on the secondary market at times. These cars were offered in two-tone grey Southern Pacific and as I recall, at a minimum the coaches were offered in SP Daylight.
GGD also offered the Harriman cars in SP, but I'm trying to remember if they were done in the Daylight scheme. I should know as I did the graphic master drawings for them! It's been a few years.
To the locomotive, the MTH model in Proto-2 or Proto-3 is a good model. Lionel's various more recent offerings are well done as well. The 3rd Rail one is a better detailed model and more accurate overall. The Williams model is a good entry level scale locomotive. I have a Williams that is a stellar runner. No frills, no command, and a little lacking on detail, but overall a nice scale locomotive. I paid somewhere around $350.00 for mine.
The short answer after my book is that you have a lot of options for the SP GS4 and probably can't go wrong on most of them since you are willing to do the work to upgrade the electronics.