This is my thoughts, surely the sensible option is for Accurascale to explore the rolling stock avenue. Mk2B and C would be welcome, Dapol have done the siphon so is there a market there. But possibly the HUO/HTV range, would MGR wagons prove popular if you can order en masse and get 30-40 wagons in one go as per the real trains.
I have approx 20 Farish/Peco/Minitrix HAA's that I have bought over a few years but not exactly going mad to get them so I would happily get an Accurascale rake if I could complete it in one hit.