For fans of JNR era express dmus (count me as one), Tenshodo is releasing a new production of kiha 58 railcars (and associated types), fitted with quantum sound. Release this summer, prices TBD.
http://www.tenshodo.co.jp/models/product/release/kiha58_p/tabid/879/Default.aspx
Also, Kato is doing a reissue of their kiha 58 series, I'll certainly pick up a couple, especially the kiro 28, I don't have that one yet. (also this summer)
http://www.katomodels.com/ho/kiha28_58/
quantum sound on a Tenshodo kiha 52:
*I like the idling sound, not so crazy about the sound when running though, too tractorlike, not the sound of the dmh17h under load.