Bachmann's new 1/20 2-8-0 (and their other 1/20 Spectrum locos) are wonderful and cheap. I would guess that, since the HO market is so huge compared with large scale, and the tooling not nearly so large and expensive, that if a manufacturer wanted to do a particular loco, they would. Someone just needs to convince them what is wanted.
Consider this, the Bman 1/20 2-8-0's are going for as little as 300 bucks these days (I think the MSRP was around $800). At those prices, Bman could have made a K-27 / 28 or EBT loco for $500-600 (certainly less than $1000) and sold about a zillion of them!!!!
Later, Gary