Keeping to N scale versions of your existing range, except those already done in conjunction with RevolutioN, as requested, I will suggest the following :
Class 50
Class 89
Mark 2 coaches, all of them
MGR wagons
Accurablokes, particularly the loco crews
Additionally, I would like to see a competing range of Mk1 coaches in N, maroon and blue/grey, as these are needed to go with many of the locos, available or in progress. Packs of four at regular intervals would go down well.