Lionel's R-27, R 30 and R 16's are scaled pretty nicely and have very realistic operating doors and sound systems , especially when used with the Legacy system as they were designed for.Mth offer's their Premier line which is pretty much to scale and offers the R-1 type's which are really detailed for that age group, but the really detailed ones are the R 32's and the R 38's in my opinion.the doors manually open on the r 32's with a type of slide system. The smaller IRT versions in the Railking line are less detailed with cast on parts, but could be reworked if you use the Q- car works details, in fact they make scale model kits for the R 17s, but i do not know if you want to build a train set from scratch, Gman.